Related Experiment Videos
Genotype/phenotype correlation in autosomal recessive lamellar ichthyosis
H C Hennies1, W Küster, V Wiebe
1Institute of Human Genetics, Charité, Humboldt University, Berlin, Germany.
American Journal of Human Genetics
|May 23, 1998
Summary
Autosomal recessive lamellar ichthyosis shows genetic heterogeneity with at least three loci identified. Current clinical criteria cannot distinguish between these molecularly distinct forms of the disease.
Area of Science:
- Genetics
- Dermatology
- Molecular Biology
Background:
- Autosomal recessive lamellar ichthyosis (ARLI) is a severe congenital disorder of keratinization.
- It presents with widespread erythema and variable scaling patterns.
- Recent studies identified mutations in the TGM1 gene and mapped a second locus to chromosome 2.
Purpose of the Study:
- To investigate genotype/phenotype correlations in 14 families with lamellar ichthyosis.
- To confirm genetic heterogeneity and identify disease loci.
- To assess the consistency between clinical and molecular classifications of ARLI.
Main Methods:
- Linkage analysis using microsatellites.
- Exclusion mapping on chromosomes 2 and 20.
- TGM1 gene sequencing.
Main Results:
- Genetic heterogeneity for ARLI was confirmed, with at least three loci involved.
- Seven novel TGM1 gene mutations (six missense, one splice) were identified in linked families.
- No genotype/phenotype correlation was found for TGM1 mutations.
- Clinical presentation did not differ between TGM1-linked and unlinked patients.
Conclusions:
- Clinical classification of lamellar ichthyosis is inconsistent with molecular findings.
- Existing clinical criteria cannot differentiate between the molecularly distinct forms of ARLI.
- Further research is needed to refine diagnostic and classification approaches for ARLI.