No HLA-A gene detectable on one of the haplotypes in a Caucasian family.
An unusual haplotype was detected in a family of a caucasian transplant patient. Human leukocyte antigen (HLA) analysis of the family demonstrated the absence of HLA-A on one of the haplotypes present in two family members. One was serologically typed A24, the other A2. Because they had one haplotype in common, the HLA-A allele of the shared haplotype was supposed to be a null allele. Different molecular typing methods identified only one allele in both individuals. The results suggest a deletion of the complete HLA-A gene or a major part of it. For confirmation, microsatellite analysis of the HLA-A region was performed with six microsatellite markers. Both family members were heterozygous for all markers, and a deletion of HLA-A could not be proven. Fluorescent in situ hybridization (FISH) was performed with cosmid and PAC probes encompassing the HLA-A gene. Both probes demonstrated an identical normal distribution pattern for diploid results. The absence of any serologic and molecular reaction with the results of the microsatellite and FISH analysis make a deletion of a narrow region, encompassing the HLA-A gene, the most plausible explanation.
Swelsen
Wendy T N
WT
Tissue Typing Laboratory, University Hospital Maastricht, Maastricht, The Netherlands.
Voorter
Christina E M
CE
Tilanus
Marcel G J
MG
Kamps
Miriam A F
MA
van den Berg-Loonen
Ella M
EM
D017931:DNA Primers; D005260:Female; D017353:Gene Deletion; D015234:HLA-A Antigens / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D018895:Microsatellite Repeats; D010375:Pedigree; D016133:Polymerase Chain Reaction; D044465:White People
D017931:DNA Primers; D015234:HLA-A Antigens