[Oculocutaneous albinism in French overseas territories (Reunion, French Guyana, Martinique) and Mayotte. Study of 21 cases in 16 families].
The dual purpose of this study was to determine the genotype of patients with oculocutaneous albinism type 1 and 2 based on analysis of tyrosinase and P gene mutations and to attempt to establish a correlation between phenotype and genotype. This study included a total of 21 Caucasian, Indian and Black African patients from La Reunion, la Martinique, French Guyana and Mayotte. PCR-sequencing of genomic DNA was performed to detect tyrosinase gene mutations and PCR-separation of PCR products by agarose gel electrophoresis was performed to detect 2.7kb deletion allele of the P gene. Tyrosinase gene mutations were identified in two cases, i.e., on eheterozygous guanine "g" deletion (c.572 delG) with a frameshift (Gly191fs) resulting in apremature termination signal at codon 225 in a Caucasian patient from La Reunion and one homozygous missense mutation, Glycine419Arginine, in an Indian patient from La Reunion. The 2.7-kb deletion allele of the P gene was detected in three Black African patients, i.e. two in the homozygous state in siblings from Mayotte and one in the heterozygous state in a girl from la Martinique. The latter patient whose mother was from la Martinique inherited the mutation from her father who was from Cameroon. This study shows that characterization of tyrosinase and P gene mutations in albinos patients is crucial to (a) differentiate subjects with oculocutaneous albinism types 1 and 2 and establish a correlation between phenotype and genotype, (b) identify healthy heterozygous carriers among the patient's immediate family (parents and siblings) and (c) allow prenatal diagnosis during subsequent pregnancies in couples who have already engendered albino children with severe visual phenotype and documented mutation(s).
Aquaron
R
R
Laboratoire de biochimie et de biologie moléculaire, faculté de médecine, Marseille, France. robert.aquaron@medecine.univ-mrs.fr
Berge-Lefranc
J L
JL
Badens
C
C
Roche
J
J
Fite
A
A
Sainte-Marie
D
D
Piquion
N
N
Cartault
F
F
D000293:Adolescent; D000328:Adult; D016115:Albinism, Oculocutaneous / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D017507:Comoros; D005260:Female; D005616:French Guiana; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D008395:Martinique; D026901:Membrane Transport Proteins / Q000235:genetics*; D008875:Middle Aged; D014442:Monophenol Monooxygenase / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D017508:Reunion
D026901:Membrane Transport Proteins; C489600:OCA2 protein, human; D014442:Monophenol Monooxygenase