A founder effect of c.1938delC in ITGB4 underlies junctional epidermolysis bullosa and its application for prenatal testing.

Junctional epidermolysis bullosa associated with pyloric atresia (JEB-PA) is one of the most severe inherited skin diseases, characterized by generalized blister formation and occlusion of the pylorus at birth. Most JEB-PA patients have mutations in the gene encoding β4 integrin (ITGB4). No recurrent mutations in ITGB4 have been described as having founder effects. We collected three JEB-PA families with c.1938delC in ITGB4. Haplotype analysis using single nucleotide polymorphism markers throughout ITGB4 suggested one rare haplotype (2.8% of the Han Chinese and ethnic Japanese populations) in all alleles with c.1938delC. The parents of one of the three families sought prenatal diagnosis for a subsequent pregnancy. We succeeded in performing prenatal exclusion of JEB-PA using the foetal genomic DNA. Our study clearly demonstrated that recurrent c.1938delC in ITGB4 is a founder mutation in JEB-PA patients, and that genotyping of the mutation can be utilized for prenatal diagnosis of JEB-PA.