Transient bullous dermolysis of the newborn: a novel de novo mutation in the COL7A1 gene.

Background: Bullous dermolysis of the newborn (BDN), an extremely rare clinical type of dystrophic epidermolysis bullosa (DEB), is characterized by subepidermal blistering at birth or shortly thereafter, followed by rapid improvement with minimal scarring or pigmentation. A total of 38 cases have been reported in the literature since the disease was initially described in 1985, but only 14 mutations in COL7A1, the gene responsible for the disease, have been detected in families with BDN.

Objectives: We report a Chinese male infant with BDN and indirect inguinal hernia, in whom a novel de novo mutation in COL7A1 was demonstrated.

Methods: DNA was obtained from the blood of the patient and his parents. The coding exon and flanking regions of COL7A1 gene were amplified by polymerase chain reaction and subjected to sequence analysis.

Results: Sequencing showed a heterozygous substitution of guanine by adenine at nucleotide position 6136 of exon 73 in the triple helical domain of type VII collagen, which predicts a change of glycine by serine at position p.G2046S. The mutation was considered to be a pathogenic and de novo mutation.

Conclusions: The coexistence of BDN and indirect inguinal hernia may simply be coincidental. These data contribute to the expanding database of COL7A1 mutations in DEB and should be useful for genetic counseling and prenatal diagnosis in affected families.