These infants are subject to early death within a
few months (mean = 12.5 weeks). The clinical features involve head (high forehead, flat
facies, cleft palate, micrognathia, characteristic eye changes, including
mongoloid slant, hypertelorism, Brushfield spots, cataracts, pigmentary
retinopathy, and optic nerve dysplasia) and central nervous system (CNS)
(seizures, absent Moro reflex). Prenatal growth failure, failure to thrive, poor
suck, muscular hypotonia, mental retardation, areflexia, deafness and congenital
heart defects (patent ductus arteriosus, septal defects, aortic abnormalities) can
be observed. Others features include apneas, polycystic kidneys, cryptorchidism,
hepatomegaly, jaundice, mitochondrial abnormalities, liver cirrhosis,
camptodactyly, talipes equinovarus, and stippled chondral calcification.