An unusual form of spinal muscular atrophy with mental retardation occurring in an inbred population

Genetic aspects of erythropoietic protoporphyria

An exhaustive study of erythropoietic protoporphyria in the Netherlands led to the discovery of 200 patients with this disorder in 91 families. In 46 of these families a single patient occurred. A study of parents, sibs and children led to the conclusion that the disease of erythropoietic protoporphyria is inherited as an autosomal recessive disorder. The presence of an occasional fluorescent red blood cell combined with normal protoporphyrin levels was observed in half of the children and sibs of patients and one of their parents; this phenomenon is therefore inherited as an autosomal dominant character. From an analysis of the findings in the 91 families we put forward the hypothesis of a 3-allele system.

Juvenile neurogenic muscle atrophy with lysosomal enzyme deficiencies: new disease or variant of mucopolysaccharidosis?

An 18-year-old boy showed childhood onset of mental retardation, neurogenic muscle atrophy with hyperreflexia, Marfan-like features, multiple epiphyseal dysplasia, increased urinary excretion of dermatan sulfate, and decreased lysosomal enzyme activities in beta-galactosidase, beta-glucuronidase, and N-acetyl-beta-D-glucosaminidase. This case may be a new syndrome, the combination of neurogenic muscle atrophy with lysosomal enzyme deficiencies.