A Recurrent Variant in in Five Siblings with Severe Respiratory Disturbance after Birth.

Schaaf-Yang syndrome (SHFYNG) is caused by truncating mutations in the paternal allele of the gene located in the Prader-Willi syndrome region. We report 5 newborns affected with SHFYNG in one family. Trio exome analysis revealed a heterozygous c.1996dupC frameshift mutation in inherited from the unaffected father. The phenotypes showed strong resemblance, especially for severe respiratory disturbance requiring mechanical ventilation at birth. After discharge from the hospital, 4 of the patients died of respiratory insufficiency within 1 or 2 weeks after birth, and 1 child died after 110 days of aggravated apnea. Apnea or respiratory failure was the main cause of early death in this family. Respiratory distress is a common manifestation of SHFYNG, especially in patients with c.1996dupC mutations. Hypotonia is a main cause of respiratory disturbance, and we propose another possible cause affecting the respiratory center of the brain.