Corneal abnormalities in a mother and daughter with focal dermal hypoplasia (Goltz-Gorlin syndrome)

PURPOSE/METHODS

Focal dermal hypoplasia is an inherited dermatologic disorder commonly associated with skeletal and dental abnormalities. Ocular abnormalities frequently found in patients with focal dermal hypoplasia include microphthalmos, anophthalmos, and colobomas. Corneal abnormalities rarely have been described in patients with focal dermal hypoplasia. We examined a mother and daughter with focal dermal hypoplasia with distinctive corneal lesions.

RESULTS/CONCLUSION

Several discrete vascularized peripheral subepithelial corneal opacifications were present bilaterally in both patients with focal dermal hypoplasia. No ocular abnormalities that would predispose to these abnormalities were found. These corneal lesions appear to represent an unusual manifestation of focal dermal hypoplasia.

Asp187Asn mutation of gelsolin in an American kindred with familial amyloidosis, Finnish type (FAP IV)

Familial amyloidosis, Finnish type (FAP-IV) was identified clinically in an American kindred with Scandinavian ancestry. A polymerase chain reaction (PCR)-based DNA diagnostic assay was used to identify a G-to-A mutation at position 654 of the gelsolin cDNA (G654A) in this family. Molecular diagnostic testing demonstrated the mutation in individuals in three generations--the clinically affected proband, here deceased clinically affected father, and her presumably affected presymptomatic child. This report represents a rare example of FAP IV and the G654A mutation identified in a family outside Finland. The disease-associated haplotype was similar to that observed in Finnish FAP IV families (suggesting common distant ancestry).

A novel mutation in medium chain acyl-CoA dehydrogenase causes sudden neonatal death

Medium chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common known genetic disorder of fatty acid oxidation. Most (approximately 80%) cases are homozygous for a single mutation: A to G replacement at nucleotide 985 (A985G). MCAD deficiency typically presents in the second year of life as hypoketotic hypoglycemia associated with fasting and may progress to liver failure, coma, and death. Prompt diagnosis and management may prevent long-term sequelae. MCAD deficiency was verified by analysis of urinary acylglycine and serum acylcarnitine species from two neonates referred for diagnosis. Full-length cDNA and MCAD exon 7 and 11 genomic clones were prepared for sequence analysis. Normal and mutant cDNAs were expressed in bacteria, and enzymatic activity was assayed by the ferricenium hexaflurophosphate method. Four compound heterozygote individuals from two unrelated families with A985G on one allele and a novel G to A mutation at nucleotide 583 (G583A) as the second mutant allele presented with MCAD deficiency in the first week of life. The expressed G583A mutant protein lacks enzymatic activity. This novel mutation, G583A, is associated with severe MCAD deficiency causing hypoglycemia or sudden, unexpected neonatal death. This previously unrecognized phenotype of MCAD deficiency may contribute significantly to preventable infant deaths.

Autosomal dominant transmission of acrodysostosis

A mother and daughter with acrodysostosis are described. This documented parent-to-child transmission supports the hypothesis of autosomal dominant inheritance of acrodysostosis. The daughter exhibited many features of acrodysostosis by two months of age, demonstrating that acrodysostosis may be diagnosed in infancy.

Osteogenesis imperfecta

Recent biochemical, linkage, and molecular genetic studies have demonstrated that, in almost every instance, osteogenesis imperfecta results from mutations in the genes that encode the chains of type I collagen. Such studies have done much to improve our understanding of the molecular basis of brittle bone disease, and have provided significant inroads into molecular diagnosis and prognostic counseling. Nonetheless, further investigation is needed urgently to identify forms of medical therapy that will decrease morbidity in osteogenesis imperfecta.

Cytochalasin B facilitates the inhibition of human polymorphonuclear leukocyte generation of superoxide by verapamil

Several functions of the human neutrophil are dependent upon extracellular calcium for optimal activation. We studied the calcium dependency of human polymorphonuclear leukocyte (PMN) superoxide generation in response to opsonized zymosan particles and its modulation by the calcium channel antagonist verapamil. PMNs were isolated from anticoagulated blood after Ficoll-Hypaque density centrifugation. The isolated PMNs were incubated with opsonized zymosan particles. The superoxide anion generated was measured by a cytochrome C reduction assay. When PMNs were incubated with opsonized zymosan in a calcium-free buffer, there was 0.45 +/- 0.06 nmol of cytochrome C reduced per 1 X 10(6) PMN per minute. This increased to 0.76 +/- 0.12 nmol per 1 X 10(6) PMN per minute when 0.6 mmol/L Ca++ was present. Moreover, if the PMNs were incubated with cytochalasin B (5 micrograms/ml), the generation of superoxide anion was further enhanced. If the same experiments were conducted in the presence of verapamil, 100 mumol/L, superoxide generation was inhibited by 51.5% +/- 8.4%. For verapamil to inhibit superoxide generation, cytochalasin B was necessary. Our results suggest that verapamil-sensitive calcium channels may exist in human PMNs, and the demonstration of their presence is cytochalasin B-dependent.