Myelination is a complex, developmentally regulated process whereby myelin proteins and lipids are coordinately expressed by myelinating glial cells. Homozygosity mapping in nine patients with childhood onset spasticity, dystonia, cognitive dysfunction, and periventricular white matter disease revealed inactivating mutations in the FA2H gene. FA2H encodes the enzyme fatty acid 2-hydroxylase that catalyzes the 2-hydroxylation of myelin galactolipids, galactosylceramide, and its sulfated form, sulfatide. To our knowledge, this is the first identified deficiency of a lipid component of myelin and the clinical phenotype underscores the importance of the 2-hydroxylation of galactolipids for myelin maturation. In patients with autosomal-recessive unclassified leukodystrophy or complex spastic paraparesis, sequence analysis of the FA2H gene is warranted.

Clinicians might minimize the prevalence of behavioral disorders among mentally retarded people. Decreased attention, hyperactivity, and impulsivity are frequently reported in children with Down syndrome, yet the exact prevalence of attention-deficit/hyperactivity disorder (ADHD) has not been clearly estimated in this population. The objective of this study was to estimate the prevalence of ADHD in children with Down syndrome and to emphasize the possible relationship between ADHD symptoms and the level of mental retardation and common medical comorbidity. In this study, the prevalence of ADHD among Down syndrome children was very high, reaching 43.9%. No significant correlation was found between ADHD symptoms and the level of mental retardation, but significant correlation was found with ophthalmologic problems. We conclude that children with Down syndrome are at increased risk for ADHD. When evaluating children with Down syndrome for attention deficits, psychiatric comorbidity as well as medical problems should be carefully taken into consideration.

No abstract

No abstract