Contributors: Sherif M. El-Harazi, Helen A. Mintz-Hittner and Frank L. Kretzer
Rhizomelic Conradi syndrome (autosomal recessive Conradi syndrome) is a rare lethal inherited syndrome with an autosomal recessive mode of inheritance characterized by both cutaneous findings and transient radiological skeletal abnormalities. It is one type Conradi syndrome. The rhizomelic Conradi syndrome is characterized by shortening of the upper extremities, a typical dysmorphic facial appearance, severe mental retardation, and congenital cataracts [cataract - congenital]. The incidence of the disease is not clear, but it has been estimated to occur in at least 1 in 500,000 births. The syndrome is a peroxisomal disorder due to reduced activity dihydroxyacetonephosphate acetyltransferase. Like other types of Conradi syndrome affected individuals have characteristic facies consisting of short neck, frontal bossing, saddle nose, high arched palate, and hypertelorism. Histopathologic abnormalities of the eye has been reported in this lethal disorder. The most common eye anomaly is congenital bilateral cataracts that are dense and symmetric. When cataracts are removed optic atrophy is clinically apparent The lethal, autosomal recessive, rhizomelic type, has severe and symmetric proximal shortening of the extremities with marked metaphyseal changes. The skin has congenital ichthyosis [ichthyosis - congenital] with hypertrophy of the stratum corneum. The hair and nail are unaffected. Neuronal atrophy with severe retardation is uniform. Abnormalities of the blood vessels include defective valves.