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A number sign (#) is used with this entry because pachyonychia congenita-4 (PC4) is caused by heterozygous mutation in the KRT6B gene (148042) on chromosome 12q13. Description Pachyonychia congenita (PC) is an autosomal dominant genodermatosis with the main clinical features of hypertrophic nail dystrophy, painful and highly debilitating plantar keratoderma, oral leukokeratosis, and a variety of epidermal cysts. Although the condition had previously been subdivided clinically into Jadassohn-Lewandowsky PC type 1 and Jackson-Lawler PC type 2, patients with PC were later found to have a mixed constellation of both types, leading to a classification of PC based on genotype (summary by Sybert, 2010; Eliason et al., 2012; McLean et al., 2011). For a discussion of genetic heterogeneity of pachyonychia congenita, see 167200. Historical Classification of Pachyonychia Congenita Gorlin et al. (1976) suggested that 2 distinct syndromes are subsumed under the designation pachyonychia congenita.
Pachyonychia congenita (PC) is a rare genodermatosis predominantly featuring painful palmoplantar keratoderma, thickened nails, cysts and whitish oral mucosa. Epidemiology The prevalence is not known but approximately 1000 patients have been registered to date worldwide. Clinical description PC presents clinically as a spectrum of conditions. PC onset is variable with most cases manifesting soon after birth, others becoming clinically apparent only in late childhood and rarely in adulthood. The first signs of the disease usually are thickened nails or neonatal teeth.
Pachyonychia congenita (PC) is a rare inherited condition that primarily affects the nails and skin. The fingernails and toenails may be thickened and abnormally shaped . Affected people can also develop painful calluses and blisters on the soles of their feet and less frequently on the palms of their hands ( palmoplantar keratoderma ). Additional features include white patches on the tongue and inside of the mouth (leukokeratosis); bumps around the elbows, knees, and waistline (follicular hyperkeratosis); and cysts of various types including steatocystoma. Features may vary among affected people depending on their specific mutation.
For a phenotypic description and a discussion of genetic heterogeneity of pachyonychia congenita, see 167200. Inheritance Chong-Hai and Rajagopalan (1977) suggested autosomal recessive inheritance of pachyonychia congenita in a 4-year-old Malaysian girl with first-cousin parents, although they recognized new dominant mutation as a possibility. See also Sivasundram et al. (1985). INHERITANCE - Autosomal recessive HEAD & NECK Mouth - No oral leukoplakia SKIN, NAILS, & HAIR Skin - Horny papules (face, leg, buttocks) - No palmoplantar hyperkeratosis - No hyperhidrosis Nails - Episodic inflammatory swelling of nail bed - Recurrent shedding of nails - Hard,thickened nails (pachyonychia) - Subungual hyperkeratosis MISCELLANEOUS - See also pachyonychia congenita, type 3 (PC1, 167200 ) ▲ Close
A number sign (#) is used with this entry because pachyonychia congenita-3 (PC3) is caused by heterozygous mutation in the keratin-6a gene (KRT6A; 148041) on chromosome 12q13. Description Pachyonychia congenita (PC) is an autosomal dominant genodermatosis with the main clinical features of hypertrophic nail dystrophy, painful and highly debilitating plantar keratoderma, oral leukokeratosis, and a variety of epidermal cysts. Although the condition had previously been subdivided clinically into Jadassohn-Lewandowsky PC type 1 and Jackson-Lawler PC type 2, patients with PC were later found to have a mixed constellation of both types, leading to a classification of PC based on genotype (summary by Sybert, 2010; Eliason et al., 2012; McLean et al., 2011). For a discussion of genetic heterogeneity of pachyonychia congenita, see 167200. Historical Classification of Pachyonychia Congenita Gorlin et al. (1976) suggested that 2 distinct syndromes are subsumed under the designation pachyonychia congenita.
A number sign (#) is used with this entry because of evidence that pachyonychia congenita-2 (PC2) is caused by heterozygous mutation in the KRT17 gene (148069) on chromosome 17q21. Description Pachyonychia congenita (PC) is an autosomal dominant genodermatosis with the main clinical features of hypertrophic nail dystrophy, painful and highly debilitating plantar keratoderma, oral leukokeratosis, and a variety of epidermal cysts. Although the condition had previously been subdivided clinically into Jadassohn-Lewandowsky PC type 1 and Jackson-Lawler PC type 2, patients with PC were later found to have a mixed constellation of both types, leading to a classification of PC based on genotype (summary by Sybert, 2010; Eliason et al., 2012; McLean et al., 2011). For a discussion of genetic heterogeneity of pachyonychia congenita, see 167200. Historical Classification of Pachyonychia Congenita Gorlin et al. (1976) suggested that 2 distinct syndromes are subsumed under the designation pachyonychia congenita.
A number sign (#) is used with this entry because pachyonychia congenita-1 (PC1) is caused by heterozygous mutation in the keratin-16 gene (KRT16; 148067) on chromosome 17q21. Description Pachyonychia congenita (PC) is an autosomal dominant genodermatosis with the main clinical features of hypertrophic nail dystrophy, painful and highly debilitating plantar keratoderma, oral leukokeratosis, and a variety of epidermal cysts. Although the condition had previously been subdivided clinically into Jadassohn-Lewandowsky PC type 1 and Jackson-Lawler PC type 2, patients with PC were later found to have a mixed constellation of both types, leading to a classification of PC based on genotype (summary by Sybert, 2010; Eliason et al., 2012; McLean et al., 2011). Historical Classification of Pachyonychia Congenita Gorlin et al. (1976) suggested that 2 distinct syndromes are subsumed under the designation pachyonychia congenita. PC type 1, the Jadassohn-Lewandowsky type, shows oral leukokeratosis.
In Dogger Bank itch, sensitivity is acquired after repeated handling of the sea chervils that become entangled in fishing nets. [ citation needed ] The specific toxin responsible for the rash was determined to be the sulfur -bearing salt (2-hydroxyethyl) dimethylsulfoxonium chloride.  This salt is also found in some sea sponges and has potent in vitro activity against leukemia cells.  Treatment [ edit ] A study of two cases in 2001 suggests that the rash responds to oral ciclosporin . ... The sea chervil, abundant in the area, frequently came up with the fishing nets and had to be thrown back into the water. ... Andrews' Diseases of the Skin: clinical Dermatology . Saunders Elsevier. ISBN 978-0-7216-2921-6 . ^ Bonnevie, P. (1948). ... Comparative Biochemistry and Physiology B . 128 (1): 27–30. doi : 10.1016/S1096-4959(00)00316-X . CS1 maint: multiple names: authors list ( link ) ^ a b Bowers PW, Julian CG., PW; Julian, CG (2001).
Characteristics [ edit ] Botellón usually begins around 11:00 p.m. and ends around 3:00 a.m. when many people move to a bar or club. ... Since botellón is usually a nighttime activity, Spain passed a law that prohibits stores to sell alcohol to the public after 10:00 p.m, hoping to persuade people to attend clubs or bars where alcohol must remain on site. [ citation needed ] However, the measure is a controversial one because people can still buy alcohol before the selling limit hour and consume it in public. ... One example of a macro-botellón was on 17 March 2006, "Half of Spain [met] on the net to organize a macro-botellón".  The macro-botellón was organized in cities around Spain, such as Madrid, Barcelona, Sevilla, Oviedo, Murcia, Vitoria, Málaga, Córdoba, Granada, and Jaén.  One of the purposes of the macro-botellón on 17 March 2006, near the Faro de Moncloa in Madrid, Spain, was to protest against the municipal restrictions on drinking alcohol in the streets. ... CS1 maint: archived copy as title ( link ) ^ "Media España se cita en la Red para celebrar un macrobotellón el 17 de marzo" . 2006-03-07. ^ http://www.20minutos.es/noticia/97295/0/macrobotellones/ciudades/espana/ | Literally translated from Spanish ^ "El Ayuntamiento "no consentirá" el macrobotellón que se prepara en Moncloa" . 2006-03-07.
. ^ "Deaths in the district of Inveresk and Musselburgh in the County of Edinburgh" . Statutory Deaths 689/00 0032 . ScotlandsPeople . Retrieved 11 April 2015 . External links [ edit ] Classification D ICD-O : 8011/0, 8011/3 Wikimedia Commons has media related to Epithelioma .
The chalky grayish-white particles within the tumor mass correspond to foci of cartilage on histology; the semi-translucent membrane covering the lens in some tumors corresponds to spreading neoplastic cells.   Tumor cells form a characteristic diktyomatous pattern, with folded cords and sheets resembling a fisherman's net.  In early development of the retina, the medullary epithelial cells acquire polarity, such that a basement membrane associated with the vitreous forms the internal limiting membrane on one side, while terminal bars form the outer limiting membrane on the other side. ... American Journal of Ophthalmology . 130 (3): 364–366. doi : 10.1016/S0002-9394(00)00542-0 . ^ a b c d e Vajaranant, Thasarat S.; Mafee, Mahmood F.; Kapur, Rashmi; Rapoport, Mark; Edward, Deepak P. ... American Journal of Ophthalmology . 133 (6): 841–843. doi : 10.1016/S0002-9394(02)01432-0 . ^ Janss, Anna J.; Yachnis, Anthony T.; Silber, Jeffrey H.; Trojanowski, John Q.; Lee, Virginia M.
Medulloepithelioma of the central nervous system is a rare, primitive neuroectodermal tumor characterized by papillary, tubular and trabecular arrangements of neoplastic neuroepithelium, mimicking the embryonic neural tube, most commonly found in the periventricular region within the cerebral hemispheres, but has also been reported in brainstem and cerebellum. It usually presents in childhood with headache, nausea, vomiting, facial nerve paresis, and/or cerebellar ataxia, and typically has a progressive course, highly malignant behavior and poor prognosis. Hearing and visual loss have also been observed.
Medulloepithelioma Histopathology of medulloepithelioma showing characteristic neural tube like strands. Specialty Neurosurgery , oncology Medulloepithelioma is a rare, primitive, fast-growing brain tumour thought to stem from cells of the embryonic medullary cavity .  Tumours originating in the ciliary body of the eye are referred to as embryonal medulloepitheliomas,  or diktyomas .  A highly malignant undifferentiated primitive neuroepithelial tumour of children, medulloepithelioma may contain bone , cartilage , skeletal muscle , and tends to metastasize extracranially.  Contents 1 Signs and symptoms 2 Diagnosis 2.1 Classification 3 Treatment 4 Prognosis 5 Epidemiology 6 References 7 External links Signs and symptoms [ edit ] Medulloepithelioma have been reported to occur in the cerebral hemispheres , brainstem , cerebellum , and peripheral sites .     Due to rapid growth of the tumour, patients typically present with increased intracranial pressure , seizures , and focal neurologic signs .  Diagnosis [ edit ] Neuronal differentiation, ranging from neuroblasts to ganglion cells, is seen in some medulloepitheliomas. Imaging studies such as Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI) can aid diagnosis . Medulloepithelioma appears isodense or hypodense with variable heterogeneity and calcification on non-contrast CT scan, and enhances with contrast.  This radiographical finding is consistent with a primitive neuroectodermal tumour, especially in children.  Blood studies and imaging studies of the abdomen may be used to detect metastases.  Needle aspiration biopsy can be used to aid diagnosis.  Definitive diagnosis requires histopathological examination of surgically excised tumour tissues. Histologically, medulloepithelioma resemble a primitive neural tube and with neuronal, glial and mesenchymal elements.   Flexner-Wintersteiner rosettes may also be observed.  Immunohistochemically , neural tube-like structures are vimentin positive in the majority of medulloepitheliomas.  Poorly differentiated medulloepitheliomas are vimentin negative.
The Lancet . 156 (4011): 89–95. doi : 10.1016/S0140-6736(00)65681-7 . ^ Weisse, Martin E (31 December 2000). ... The Lancet . 357 (9252): 299–301. doi : 10.1016/S0140-6736(00)03623-0 . PMID 11214144 . S2CID 35896288 . ^ Powell, KR (January 1979). ... The Journal of Pediatrics . 78 (6): 958–67. doi : 10.1016/S0022-3476(71)80425-0 . PMID 4252715 . ^ Morens, David M; Katz, Alan R; Melish, Marian E (31 May 2001). ... The Lancet . 357 (9273): 2059. doi : 10.1016/S0140-6736(00)05151-5 . PMID 11441870 . S2CID 35925579 .
A rare staphylococcal toxemia caused by epidermolytic toxins of Staphylococcus aureus and characterized by the appearance of widespread erythematous patches, on which large blisters develop. Upon rupture of these blisters, the skin appears reddish and scalded. The lesions typically begin in the face and rapidly expand to other parts of the body. The disease may be complicated by pneumonia and sepsis. It most commonly affects newborns and infants.
The Lancet . 156 (4011): 89–95. doi : 10.1016/S0140-6736(00)65681-7 . ^ a b c d Weisse, ME (31 December 2000). ... The Lancet . 357 (9252): 299–301. doi : 10.1016/S0140-6736(00)03623-0 . PMID 11214144 . S2CID 35896288 . ^ Dukes-Filatov disease at Who Named It?
Clin Dermatol . 19 (1): 69–71. doi : 10.1016/S0738-081X(00)00215-7 . PMID 11369491 . ^ "Drugs that call for extra caution. ... New York: Simon Schuster. p. 56. ISBN 978-0-684-87309-1 . ^ M.d. Kamath, Bob (30 May 2007). ... Kendall Hunt Publishing. p. 25. ISBN 978-0-7872-8701-6 . ^ Ashton CH (2002).
Clinical Features Lisch et al. (1992) described 5 family members and 3 unrelated patients (4 males, 4 females), aged 23 to 71 years, with bilateral or unilateral, gray, band-shaped, and feathery opacities that sometimes appeared in whorled patterns. Retroillumination showed that the opacities consisted of intraepithelial, densely crowded, clear microcysts. Light and electron microscopy disclosed diffuse vacuolization of the cytoplasm of epithelial cells in the affected area. Visual acuity was so reduced in 3 patients that abrasion of the corneal epithelium was performed. The corneal abnormalities recurred within months, with the same reduction in visual acuity as before.
Lisch epithelial corneal dystrophy (LECD) is a very rare form of superficial corneal dystrophy characterized by feather-shaped opacities and microcysts in the corneal epithelium arranged in a band-shaped and sometimes whorled pattern, occasionally with impaired vision. Epidemiology Exact prevalence of this form of corneal dystrophy is not known but very few cases have been reported to date. LECD has been documented in one German family and in rare sporadic cases in Germany and the USA. Clinical description Lesions generally develop in childhood. Epithelial opacities are slowly progressive and painless blurred vision sometimes occurs after 60 years of age. Etiology The exact cause is unknown but appears to be genetic. The gene related to Lisch epithelial corneal dystrophy has been mapped to the short arm of the X chromosome (Xp22.3).
Lippincott Williams & Wilkins. pp. 254–256. ISBN 0-7817-3905-5 . ^ a b c d e f g h i Smith, Melanie N. (2006-05-10). ... Cambridge University Press . p. 77. ISBN 1-900151-51-0 . ^ Papadakis, Maxine A.; Stephen J. ... McGraw-Hill Professional. p. 60. ISBN 0-07-145892-1 . ^ a b Bosze, Peter; David M. ... Informa Health Care. p. 66. ISBN 963-00-7356-0 . ^ "Cervical Polyps" (PDF) .
A rare photodermatosis characterized by the development of pruritic or painful vesicles in a photodistributed pattern in response to sunlight exposure. The lesions heal with permanent varioliform scarring. Ocular involvement, deformities of ears and nose, or contractures of the fingers may occasionally be observed. Systemic signs and symptoms are absent. The condition typically occurs in childhood and regresses spontaneously in adolescence or young adulthood.
With giant hemangiomas in small children, thrombocytopenia and red cell changes compatible with trauma ('microangiopathic hemolytic anemia') have been observed. The mechanism of the hematologic changes is obscure. No evidence of a simple genetic basis has been discovered. Propp and Scharfman (1966) reported a male infant with thrombocytopenia associated with a large hemangioma of the right arm and axilla. The patient had low platelet counts with a markedly diminished platelet survival time and an absence of platelet agglutinin or complement-fixing antibody. Radiochromate-tagged platelet studies suggested sequestration in the hemangioma, liver, and spleen.
Hemangioma thrombocytopenia syndrome is characterized by profound thrombocytopenia in association with two rare vascular tumors: kaposiform hemangioendotheliomas and tufted angiomas . The profound thrombocytopenia can cause life threatening bleeding and progress to a disseminated coagulopathy in patients with these tumors. The condition typically occurs in early infancy or childhood, although prenatal cases (diagnosed with the aid of ultrasonography), newborn presentations, and rare adult cases have been reported.
Kasabach-Merritt syndrome (KMS), also known as hemangioma-thrombocytopenia syndrome, is a rare disorder characterized by profound thrombocytopenia, microangiopathic hemolytic anemia, and subsequent consumptive coagulopathy in association with vascular tumors, particularly kaposiform hemangioendothelioma or tufted angioma.
Fitzpatrick's Dermatology in General Medicine (6th ed.). McGraw-Hill. ISBN 0-07-138076-0 . ^ James W, Berger T, Elston D (2005). Andrews' Diseases of the Skin: Clinical Dermatology (10th ed.). Saunders. ISBN 0-7216-2921-0 . ^ Pardasani AG, Feldman SR, Clark AR (February 2000). ... Journal of the American Academy of Dermatology . 42 (5 Pt 2): 885–7. doi : 10.1016/s0190-9622(00)90263-9 . PMID 10767696 . ^ Mehlis S (2019).
Guttate psoriasis is a skin condition in which small, red, and scaly teardrop-shaped spots appear on the arms, legs, and middle of the body. It is a relatively uncommon form of psoriasis . The condition often develops very suddenly, and is usually triggered by an infection (e.g., strep throat, bacteria infection, upper respiratory infections or other viral infections). Other triggers include injury to the skin, including cuts, burns, and insect bites, certain malarial and heart medications, stress, sunburn, and excessive alcohol consumption. Treatment depends on the severity of the symptoms, ranging from at-home over the counter remedies to medicines that suppress the body's immune system to sunlight and phototherapy.
Hagerstown, MD: Lippincott Williams & Wilkins. p. 1150. ISBN 0-7817-2655-7 . Retrieved 2008-06-16 . ^ a b c d e f Scalea TM (2005). ... Boca Raton: CRC. pp. 26–32. ISBN 978-0-8493-8138-6 . Retrieved 2008-07-06 . ^ a b Porth, Carol (2007). ... Hagerstown, MD: Lippincott Williams & Wilkins. p. 838. ISBN 978-0-7817-7087-3 . Retrieved 2008-07-03 . ^ Pitkänen A, McIntosh TK (2006). ... Neurotrauma: New Insights Into Pathology and Treatment . Elsevier. pp. 13–19. ISBN 978-0-444-53017-2 . Retrieved 2008-06-10 . ^ a b Granacher RP (2007). ... Neuroscience . 101 (2): 289–95. doi : 10.1016/S0306-4522(00)00380-8 . PMID 11074152 . S2CID 20457228 . ^ Sauaia A, Moore FA, Moore EE, et al.
Avoiding mosquito bites, such as by using insecticide -treated mosquito bed nets , also reduces the transmission of lymphatic filariasis.   The Carter Center 's International Task Force for Disease Eradication declared lymphatic filariasis one of six potentially eradicable diseases.  According to medical experts, the worldwide effort to eliminate lymphatic filariasis is on track to potentially succeed by 2020.  For similar-looking but causally unrelated podoconiosis , international awareness of the disease will have to increase before elimination is possible. ... Andrews' Diseases of the Skin: clinical Dermatology . Saunders Elsevier. ISBN 978-0-7216-2921-6 . ^ a b Pfarr KM, Debrah AY, Specht S, Hoerauf A (November 2009). ... Anatomy & Physiology: The Unity of Form and Function . McGraw-Hill. ISBN 978-0-07-287506-5 . ^ a b c "Parasites - Lymphatic Filariasis" . cdc.gov . ... Wallingford: CAB International. pp. 1–848. ISBN 0-85198-689-7 . ^ Grove, David I (2014). ... Oxford: Oxford University Press. pp. 1–602. ISBN 978-0-19-964102-4 . ^ Burma D.P. (2010).
Lymphatic filariasis is a parasitic disease caused by microscopic, thread-like worms that only live in the human lymph system , which maintains the body's fluid balance and fights infections. It is spread from person to person by mosquitoes. Most infected people are asymptomatic and never develop clinical symptoms. A small percentage of people develop lymphedema , which may affect the legs, arms, breasts, and genitalia; bacterial infections that cause hardening and thickening of the skin, called elephantiasis; hydrocele (swelling of the scrotum) in men; and pulmonary tropical eosinophilia syndrome . Treatment may include a yearly dose of medicine, called diethylcarbamazine (DEC); while this drug does not kill all of the adult worms, it prevents infected people from giving the disease to someone else.
Lymphatic filariasis (LF) is a severe form of filariasis (see this term), caused by the parasitic worms Wuchereria bancrofti , Brugia malayi and Brugia timori , and the most common cause of acquired lymphedema worldwide. LF is endemic to tropical and subtropical regions. The vast majority of infected patients are asymptomatic but it can also cause a variety of clinical manifestations, including limb lymphedema, genital anomalies (hydrocele, chylocele), elephantiasis in later stages of the disease (frequently in the lower extremities), and tropical pulmonary eosinophilia (nocturnal paroxysmal cough and wheezing, weight loss, low-grade fever, adenopathy, and pronounced blood eosinophilia). Renal involvement (hematuria, proteinuria, nephritic syndrome, glomerulonephritis), and mono-arthritis of the knee or ankle joint have also been reported.
Current Opinion in Genetics & Development . 10 (3): 262–9. doi : 10.1016/s0959-437x(00)00084-8 . PMID 10826992 . ^ Rash BG, Grove EA (October 2007). ... Archived from the original on 2009-05-14. ^ Armand Marie Leroi , Mutants : On the Form, Varieties and Errors of the Human Body , 2003, Harper Perennial, London. ISBN 0-00-653164-4 ^ The Carter Center for Research in holoprosencephaly  and  Archived 2008-11-21 at the Wayback Machine ^ Hong M, Srivastava K, Kim S, Allen BL, Leahy DJ, Hu P, Roessler E, Krauss RS, Muenke M (2017) BOC is a modifier gene in holoprosencephaly. ... Human Genetics . 125 (1): 95–103. doi : 10.1007/s00439-008-0599-0 . PMC 2692056 . PMID 19057928 . ^ Tekendo-Ngongang C, Muenke M, Kruszka P (1993).
A number sign (#) is used with this entry because it represents a contiguous gene deletion syndrome. A form of holoprosencephaly (HPE10) has been mapped within the deleted region of chromosome 1q41-q42. For a general phenotypic description and a discussion of genetic heterogeneity of holoprosencephaly, see HPE1 (236100). See also congenital diaphragmatic hernia (DIH; 142340), which has been associated with deletion of chromosome 1q41-q42. See also Skraban-Deardorff syndrome (SKDEAS; 617616), caused by mutation in the WDR26 gene (617424) on chromosome 1q42, which shows overlapping features with chromosome 1q41-q42 deletion syndrome.
A number sign (#) is used with this entry because of evidence that holoprosencephaly-4 (HPE4) is caused by heterozygous mutation in the TGIF gene (602630) on chromosome 18p11. For phenotypic information and a general discussion of genetic heterogeneity in holoprosencephaly, see HPE1 (236100). Cytogenetics Johnson and Bachman (1976) described a normal female who appeared to have a nonreciprocal translocation from the short arm of one chromosome 18 to the long arm of a chromosome 12. She gave birth to a cebocephalic child whose karyotype included an 18p- chromosome. The association of loss of 18p with holoprosencephaly was suggested by the patient reported by Munke et al. (1988); cytogenetic and molecular studies indicated a Y/18 translocation with loss of 18p and distal Yq material in a holoprosencephalic fetus.
A number sign (#) is used with this entry because holoprosencephaly-11 (HPE11) is caused by heterozygous mutation in the CDON gene (608707) on chromosome 11q24. For a general phenotypic description and a discussion of genetic heterogeneity of holoprosencephaly, see HPE1 (236100). Clinical Features Bae et al. (2011) reported 4 unrelated patients with HPE11. One patient had agenesis of the corpus callosum, hypotelorism, growth hormone deficiency, global developmental delay, and thick eyebrows with synophrys. Another had agenesis of the corpus callosum, alobar HPE, hypotelorism, cleft lip/palate, and absent columella; absent pituitary and polysplenia were noted in this patient at autopsy.
For a phenotypic description and a discussion of genetic heterogeneity of holoprosencephaly, see HPE1 (236100). Clinical Features Levin and Surana (1991) described holoprosencephaly in association with an interstitial deletion of chromosome 14q11.1-q13. Parental karyotypes were normal. The white female, born to nonconsanguineous young parents after an uncomplicated pregnancy, showed hypotelorism, lack of nasal bridge, flattened nasal tip with no visible septum, wide midline cleft of lip and hard palate, and ptosis of the left upper eyelid. Axial CT scan of the head was interpreted as showing semilobar holoprosencephaly. The infant died at 8 days of age. Kamnasaran et al. (2005) reported 6 patients with HPE and interstitial deletions on proximal chromosome 14q: 1 had alobar HPE and 5 had lobar HPE.
For phenotypic information and a general discussion of genetic heterogeneity in holoprosencephaly (HPE), see HPE1 (236100). Clinical Features Lehman et al. (2001) described a female infant who survived for 5.5 hours after delivery at 33 weeks' gestation. Autopsy showed a lobar variant of holoprosencephaly. Cytogenetics By cytogenetic analysis in an infant with a lobar variant of holoprosencephaly, Lehman et al. (2001) identified a 2q37.1-q37.3 deletion. This case represented the fourth reported case of HPE associated with partial monosomy 2q37 and the first with an apparently isolated 2q37 deletion. Lehman et al. (2001) suggested that the deleted segment may contain yet another locus, here designated HPE6, which, when disrupted, can lead to brain malformations within the HPE spectrum.
Nonsyndromic holoprosencephaly is an abnormality of brain development that also affects the head and face. Normally, the brain divides into two halves (hemispheres ) during early development. Holoprosencephaly occurs when the brain fails to divide properly into the right and left hemispheres. This condition is called nonsyndromic to distinguish it from other types of holoprosencephaly caused by genetic syndromes, chromosome abnormalities, or substances that cause birth defects (teratogens). The severity of nonsyndromic holoprosencephaly varies widely among affected individuals, even within the same family.
Holoprosencephaly is an abnormality of brain development in which the brain doesn't properly divide into the right and left hemispheres. The condition can also affect development of the head and face. There are 4 types of holoprosencephaly, distinguished by severity. From most to least severe, the 4 types are alobar, semi-lobar, lobar, and middle interhemispheric variant (MIHV). In general, the severity of any facial defects corresponds to the severity of the brain defect. The most severely affected people have one central eye (cyclopia) and a tubular nasal structure (proboscis) located above the eye.
A number sign (#) is used with this entry because of evidence that holoprosencephaly-3 (HPE3) is caused by heterozygous mutation in the SHH gene (600725), which encodes the human Sonic hedgehog homolog, on chromosome 7q36. For a phenotypic description and a discussion of genetic heterogeneity of holoprosencephaly, see HPE1 (236100). Clinical Features Berry et al. (1984) and Johnson (1989) provided information on a family (family 2 in Johnson, 1989) in which holoprosencephaly occurred in 2 sibs and their first cousin, who were offspring of parents with a single central maxillary incisor. Johnson (1989) reported a second patient (family 1) with full-blown holoprosencephaly whose mother and sister had only a single central maxillary incisor. Johnson (1989) suggested that holoprosencephaly is a developmental field defect of which the mild forms can be single median incisor, hypotelorism, bifid uvula, or pituitary deficiency.
A number sign (#) is used with this entry because of evidence that holoprosencephaly-7 (HPE7) is caused by heterozygous mutation in the PTCH1 gene (601309) on chromosome 9q22. For phenotypic information and a general discussion of genetic heterogeneity in holoprosencephaly, see HPE1 (236100). Description Holoprosencephaly (HPE) is the most commonly occurring congenital structural forebrain anomaly in humans. HPE is associated with mental retardation and craniofacial malformations. Considerable heterogeneity in the genetic causes of HPE has been demonstrated (Ming et al., 2002).
A number sign (#) is used with this entry because of evidence that solitary median maxillary central incisor (SMMCI) and SMMCI syndrome are caused by heterozygous mutation in the Sonic hedgehog gene (SHH; 600725) on chromosome 7q36. Clinical Features Rappaport et al. (1976, 1977) reported 7 unrelated patients with single (unpaired) deciduous and permanent maxillary central incisors and short stature. Five of them had isolated growth hormone deficiency. The other 2 had normal growth hormone responses but were short of stature. No similar or possibly related abnormalities were present in the 7 families. Rappaport et al. (1976) used the term monosuperoincisivodontic dwarfism to describe the association of short stature and solitary incisor.
Description Holoprosencephaly (HPE) is the most common structural malformation of the human forebrain and occurs after failed or abbreviated midline cleavage of the developing brain during the third and fourth weeks of gestation. HPE occurs in up to 1 in 250 gestations, but only 1 in 8,000 live births (Lacbawan et al., 2009). Classically, 3 degrees of severity defined by the extent of brain malformation have been described. In the most severe form, 'alobar HPE,' there is a single ventricle and no interhemispheric fissure. The olfactory bulbs and tracts and the corpus callosum are typically absent.
A rare complex brain malformation characterized by incomplete cleavage of the prosencephalon, and affecting both the forebrain and face and resulting in neurological manifestations and facial anomalies of variable severity. Epidemiology Prevalence is estimated to be 1/10,000 live and still births and 1/250 conceptuses, with worldwide distribution. Clinical description Three classical forms of holoprosencephaly (HPE) of increasing severity are described based on the degree of anatomical separation: lobar, semi-lobar and alobar HPE. Milder subtypes include midline interhemispheric variant and septopreoptic HPE. There is, however, a continuous spectrum of abnormal separation of the hemispheres that extends from aprosencephaly/atelencephaly, the most severe end of the spectrum, to microform HPE, a less severe midline defect without the typical HPE brain characteristics.