Autosomal Recessive Spondylocostal Dysostosis

A rare condition of variable severity associated with vertebral and rib segmentation defects and characterised by a short neck with limited mobility, winged scapulae, a short trunk, and short stature with multiple vertebral anomalies at all levels of the spine.

Epidemiology

The incidence and prevalence are unknown. The disease seems to be more frequent in the Puerto Rican population.

Clinical description

Autosomal recessive spondylocostal dysostosis (ARSD) is usually diagnosed in the neonatal period. The main skeletal malformations include fusion of the vertebrae, hemivertebrae, and rib fusion with other rib malformations. Deformity of the chest and spine (severe scoliosis, kyphoscoliosis and lordosis) is a natural consequence of these malformations and leads to a dwarf-like appearance. As the thorax is small, infants frequently have respiratory insufficiency and repeated respiratory infections. Anomalies of the central nervous system, genitourinary tract and heart (spina bifida, meningocele, renal and ureteral abnormalities, hypospadias, complex congenital heart disease, atrial septal defect, anomalous pulmonary venous return etc.) have been reported but are not common. Facial dysmorphism and intellectual deficit are occasional features.

Etiology

So far, four genes, all involved in the Notch signalling pathway - DLL3 (19q13.2), MESP2 (15q26.1), LFNG (7p22.3) and HES7 (17p13.1) - have been identified but mutations in these genes do not account for all of the cases.

Diagnostic methods

Diagnosis is clinical and may be supported by ultrasonography and spine radiographs.

Antenatal diagnosis

Prenatal diagnosis is possible using fetal ultrasound.

Genetic counseling

The disease is inherited as an autosomal recessive trait.

Management and treatment

Management includes intensive medical care, bone surgery, and orthopedic treatment.

Prognosis

ARSD may cause respiratory insufficiency that may lead to life-threatening complications in the first year of life.