And Metabolic Disease Sponsors do not influence content. The first reports were of children with characteristic facies, low birth weight, asymmetry, and growth retardation. Over the past several years, more than 400 patients have been described with phenotypes ranging from mild to classical.
Growth failure is the primary abnormality.
Patients present with intrauterine growth retardation, difficulty feeding, failure to thrive, or postnatal growth retardation that may be due to immature osseous development through early childhood. Older children and adults do not manifest clinical features as clearly as infants or young children. Usually, growth hormone levels are normal. There is facial dysmorphism with small, triangular facies, and normal head circumference. Since length is usually less than normal, the head appears disproportionately large.