A novel locus for autosomal dominant nuclear cataract mapped to chromosome 2p12 in a Pakistani family.
OBJECTIVE
To map the disease locus in a four-generation, consanguineous Pakistani family affected by autosomal dominant congenital nuclear cataract (adNCat). All affected individuals had early onset of bilateral nuclear cataract.


METHODS
Genomic DNA from family members was typed for alleles at more than 300 known polymorphic genetic markers by polymerase chain reaction. The lod scores were calculated by using two-point linkage analysis of the genotyping data.


RESULTS
The maximum lod score, 4.05, was obtained for the marker D2S2333. Proximal and distal crossovers were observed with markers D2S286 and D2S1790, respectively. These crossovers define the critical disease locus to an interval of approximately 9 centimorgans (cM).


CONCLUSIONS
Linkage analysis identified a novel locus for adNCat on chromosome 2p12 in a Pakistani family. A genome database analysis of the target interval is being undertaken to identify candidate gene(s) for the disease.
Khaliq
Shagufta
S
Biomedical and Genetic Engineering Division, Dr. A. Q. Khan Research Laboratories, PO Box 2891, 24 Mauve Area, Islamabad, Pakistan. sqmehdi@isb.comsats.net.pk
Hameed
Abdul
A
Ismail
Muhammad
M
Anwar
Khalid
K
Mehdi
S Qasim
SQ
D000328:Adult; D000368:Aged; D002386:Cataract / Q000151:congenital / Q000235:genetics* / Q000473:pathology; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics*; D003241:Consanguinity; D004247:DNA / Q000032:analysis; D004252:DNA Mutational Analysis; D005260:Female; D005799:Genes, Dominant; D008040:Genetic Linkage; D005838:Genotype; D006801:Humans; D007907:Lens Nucleus, Crystalline / Q000473:pathology*; D008126:Lod Score; D008297:Male; D010154:Pakistan; D010375:Pedigree; D016133:Polymerase Chain Reaction
D004247:DNA