Linkage replication of the MYP12 locus in common myopia.
OBJECTIVE
Myopia is a common disorder with a large public health impact. Although 12 myopia loci have been reported and heterogeneity for high myopia loci have been demonstrated, replication of high-myopia loci with a common myopia phenotype has not been successful. This study reports the successful replication of MYP12 in three large, multigenerational families with autosomal dominant (AD) common myopia (spherical equivalent [SphE] </= -0.50 D).


METHODS
These families contained 49 participants (35 affected). The average spherical equivalent was -2.76 D (range, -0.50 to -10.25 D), average axial length was 24.52 mm (range, 23.05-27.11 mm), and average keratometry was 43.21 D (range, 39.12-47.31 D). Only five individuals in the three families presented with myopia of SphE </= -6.00 D. Glaucoma, keratoconus, lenticonus, and dislocated lens were not present in any study participants. A genomewide scan was performed using a mapping set with 400 markers at approximately 10 cM coverage. Merlin software was used for multipoint linkage analysis based on an AD model with a penetrance of 0.9 and disease allele frequency of 0.013.


RESULTS
Significant linkage with a multipoint parametric LOD score of 3.428 (P = 0.000035) and a multipoint nonparametric (Kong and Cox) LOD score of 2.37 (empiric P < 0.001) was obtained on 2q37.1, with a 1-LOD support interval that overlapped the previously reported MYP12 locus for high myopia.


CONCLUSIONS
This study provided evidence that some high-myopia loci may contribute to all degrees of myopia and indicated the likely location of a myopia gene for the low/moderate as well as the high form of myopia.
Chen
Christine Y
CY
Eye Research Australia, Australia. chris_chen30@hotmail.com
Stankovich
Jim
J
Scurrah
Katrina J
KJ
Garoufalis
Pam
P
Dirani
Mohamed
M
Pertile
Kelly K
KK
Richardson
Andrea J
AJ
Baird
Paul N
PN
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D002648:Child; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D008040:Genetic Linkage; D005838:Genotype; D006801:Humans; D008126:Lod Score; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000235:genetics*; D010375:Pedigree