Intergeneration CAG expansion and contraction in a Chinese HD family.
The prevalence of juvenile-onset Huntington's disease (HD) is about ten times lower than adult HD. Here we report a Chinese HD family showing both intergeneration CAG expansion and contraction. The expansion resulted from a paternal transmission which leads to juvenile-onset HD for a 17-year-old Chinese boy (III-5). More interestingly, a contraction was noticed in a maternal transmission (III-3), which changed the CAG repeat from an expanded, disease-causing allele (48 repeats) to a normal or intermediate allele (34 repeats). Of note, the contraction resulted in a deletion of 14 CAG repeats, which is much larger than previously reported contractions. Our results are consistent with previous observations in Western Caucasians that juvenile-onset HD is more likely inherited through the male germline.
Tang
Yanping
Y
Department of Cell Biology and Genetics, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China.
Wang
Ying
Y
Yang
Ping
P
Liu
Yuan
Y
Wang
Bo
B
Podolsky
Robert
R
McIndoe
Richard
R
Wang
Cong-Yi
CY
D000293:Adolescent; D000328:Adult; D000483:Alleles; D002681:China; D005192:Family Health; D005260:Female; D005838:Genotype; D006801:Humans; D000071058:Huntingtin Protein; D006816:Huntington Disease / Q000235:genetics*; D040582:Inheritance Patterns; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics*; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*; D018911:Trinucleotide Repeats / Q000235:genetics*
C086055:HTT protein, human; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins