Saethre-Chotzen syndrome is characterized by early fusino of certain skull bones, facial asymmetry, and variable joined fingers. Although mild-to-moderate developmental delay and mental retardation have been reported, normal intelligence is more common. TWIST1 mutations are identified in 46-80% of affected individuals using a combination of deletion/duplication analysis and sequence analysis (exon 1). Saethre-Chotzen syndrome is inherited in an autosomal dominant manner.
Galactosemia is a disorder of galactose metabolism that can result in life-threatening complications including feeding problems, bleeding, infection, and mental retardation in untreated individuals. If a lactose-galactose-restricted diet is provided right away, the symptoms resolve and further complications and mental retardation can be prevented. Galactosemia is caused by deficient activity of the enzyme galactose-phosphate uridyltransferase. This autosommal recessive disease can be detected in virtually 100% of babies in states that have newborn screening programs.