Molecular analysis of the human laminin alpha3a chain gene (LAMA3a): a strategy for mutation identification and DNA-based prenatal diagnosis in Herlitz junctional epidermolysis bullosa

Lab Invest. 1998 Sep;78(9):1067-76.

Abstract

Mutations in the genes (LAMA3, LAMB3, and LAMC2) encoding the subunit polypeptides of the cutaneous basement membrane zone protein laminin 5 have been reported in different forms of junctional epidermolysis bullosa (JEB), an inherited blistering skin disease. In this study, we present the complete exon-intron organization of the "a" transcript of the laminin alpha3 chain gene, LAMA3a, which is expressed primarily in the skin. We have performed fine-resolution mapping of this gene on chromosome 18q11.2 using a human-hamster radiation hybrid panel. We have also developed a mutation-detection strategy based on the exon-intron structure of LAMA3a. This strategy, based on PCR amplification of genomic sequences, followed by heteroduplex scanning and automated nucleotide sequencing, was used for successful mutation screening in a family with the lethal (Herlitz) type of JEB, and two novel LAMA3 mutations were identified in the proband. The mutations consisted of a single-base pair deletion in LAMA3a exon A11 on the paternal allele, designated 1239delC, and a two-base pair deletion in LAMA3a exon A23 on the maternal allele, designated 2959delGG. This information was also used for DNA-based prenatal testing in a subsequent pregnancy in this family. Collectively, these results attest to our expanding capability to elucidate the genetic basis of various forms of epidermolysis bullosa using molecular techniques.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Chromosome Mapping
  • Cricetinae
  • DNA / genetics*
  • DNA Mutational Analysis*
  • Epidermolysis Bullosa, Junctional / diagnosis*
  • Epidermolysis Bullosa, Junctional / genetics*
  • Exons / genetics
  • Female
  • Humans
  • Infant
  • Introns / genetics
  • Laminin / genetics*
  • Male
  • Molecular Sequence Data
  • Nucleic Acid Heteroduplexes / genetics
  • Pregnancy
  • Prenatal Diagnosis / methods*

Substances

  • Laminin
  • Nucleic Acid Heteroduplexes
  • laminin alpha 3
  • DNA