Globalization of DNA-based prenatal diagnosis for recessive dystrophic epidermolysis bullosa

Abstract

Globalization of economies and improvements in international telecommunications has led to increased demand for better access to the latest developments in healthcare, wherever they may be available. In this report, we describe the first case from Thailand of DNA-based prenatal testing of a mother at risk for recurrence of severe recessive dystrophic epidermolysis bullosa (RDEB), whose affected child had died in early childhood. In the absence of previous access to prenatal diagnostic tests, the mother had undergone several terminations for fear of having another affected child. To prevent this happening again, DNA from the mother and her consanguineous partner was sent from Bangkok to a specialist laboratory at St John's Institute of Dermatology in London and screened for pathogenic mutations in the COL7A1 gene: both individuals were shown to be heterozygous carriers of a splice-site mutation, c.2440G --> C. In a subsequent pregnancy, amniocentesis was performed at 18 weeks' gestation in Bangkok, and fetal DNA was extracted and sent to London for analysis. Restriction endonuclease digestion of the amplified fetal DNA revealed the wild-type COL7A1 sequence only, and 5 months later, a clinically unaffected boy was born. This case represents the first example of DNA-based prenatal diagnosis for RDEB in Thailand and illustrates the benefits for patients in establishing international links with diagnostic centres with technological expertise that is not widely available in certain countries.