[2470insG, represents the commonest mutation in Mexican patients with dystrophic bullous epidermolysis. A study of 21 families].
BACKGROUND
Type VII collagen gene (COL 7 Al) mutations are the cause of dystrophic epidermolysis bullosa (DEB), but most mutations are specific to individual families and there is limited data on the nature of COL 7 Al mutations in certain ethnic populations.


OBJECTIVE
To determine the molecular basis of DEB in Mexican patients and describe the most frequent mutation among this ethnic population.


METHODS
Most subjects were approached at FUNDACION DEBRA MEXICO AC. Molecular analysis was performed by polymerase chain reaction (PCR) of genomic DNA using COL 7 A l-specific primers, heteroduplex analysis, and direct nucleotide sequencing.


RESULTS
Fifty nine of 67 COL 7 Al possible mutations (88%) were identified; 36 individuals (31 recessive, five dominant) from 21 families. Recessive mutations included six frameshift mutations, four silent glycine substitutions and two splice site mutations.


CONCLUSIONS
The present study informs a different kind of mutation observed in our patient population. Only two mutations informed in this study had been described earlier among another ethnic group. The most frequent mutation was 2470insG, affecting 21 (58.3%) out of 36 patients with DEB. These new data will be helpful in facilitating the accurate diagnosis of an DEB subtype, and will add further insight into the pathophysiology of this mechanobullous disease.
Servicios Médicos de la Universidad Autónoma de Nuevo León, Monterrey, NL México. electronico.doctor@iuliosalas.com
Julio César
JC
Salas-Alanis
John A
JA
McGrath
D024143:Collagen Type VII / Q000235:genetics; D016108:Epidermolysis Bullosa Dystrophica / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D009154:Mutation
D024143:Collagen Type VII