North Carolina macular dystrophy (MCDR1) in Texas.
OBJECTIVE
To map the gene responsible for causing a macular degeneration in a Texan family that appears clinically similar to the North Carolina macular dystrophy (MCDR1) phenotype.


METHODS
A single family in Texas had all the typical clinical features of the North Carolina macular dystrophy phenotype. Of 23 family members examined, 10 were affected. Blood was collected from all 23 members and fundus photographs were obtained on those affected. A detailed family history consisting of nine generations was obtained. Genotyping and likelihood analysis was performed using the closest linked MCDR1 markers.


RESULTS
The genealogic data showed no relation with the original North Carolina macular dystrophy pedigree. The dinucleotide repeat marker D6S283 yielded the highest 2-point LOD score with a Zmax = 4.1 at theta = 0. The peak LOD score generated from multipoint analysis was 6.0.


CONCLUSIONS
The linkage results indicate that the macular degeneration in this Texan family is due to a mutation in the same genomic region as that causing North Carolina macular dystrophy. Furthermore, haplotype analysis suggests that the original North Carolina family and the Texan family have the same mutation and a common founder.
Small
K W
KW
The Macular Center at the Jules Stein Eye Institute, UCLA, Los Angeles, California 90095, USA.
Garcia
C A
CA
Gallardo
G
G
Udar
N
N
Yelchits
S
S
D000328:Adult; D000368:Aged; D002874:Chromosome Mapping; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics; D004247:DNA / Q000032:analysis; D005260:Female; D005787:Gene Frequency; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium; D008268:Macular Degeneration / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009657:North Carolina; D010375:Pedigree; D015995:Prevalence; D013781:Texas / Q000453:epidemiology
D005819:Genetic Markers; D004247:DNA