Medium chain acyl CoA dehydrogenase deficiency, or 'MCAD,' is a metabolic disease in which the body cannot breakdown certain fats. MCAD is the most common fatty acid disorder affecting about one in 13,000 people. Children with MCAD usually get sick for the first time during an illness that makes them not want to eat, like the flu. When their body runs out of sugar, and cannot process stored fats, affected individuals may have vomiting. diarrhea, seizures, and can sometimes die. MCAD deficiency may be the cause of one out of 100 SIDS cases.
MCAD is inherited in an autosommal recessive manner and is caused by mutations in the medium-chain acyl-CoA dehydrogenase gene (ACADM) on chromosome 1p31.
Myotonic dystrophy is a progressive degenerative neuromuscular disorder with an incidence of about one in 8000. Symptoms are variable but mainly including poor muscle control and muscle weakness, and cataracts. Myotonic Dystrophy is caused by an excessive number of CTG repeats on the DMPK gene on Chromosome 19. Severity of the symptoms depends on the number of repeats: normal individuals have from 5 to 30 repeat copies; mildly affected persons, from 50 to 80; and severely affected individuals, 2,000 or more copies. Inherited in an autosomal dominated pattern, the repeat lengths can expand when passed from parent to child.
Pfeiffer Syndrome is a condition resulting from premature fusion of the sutures of the skull and deformity of the skull. Characteristics include a prematurely fused skull (craniosynostosis), bulging wide-set eyes due to shallow eye sockets,
broad, short thumbs and big toes, occasional webbing of the hands and feet. Although most cases are due to new mutations in the FGFR 1 and FGFR2 genes, it is also inherited in an autosomal dominant pattern.