Abstract
The gene for the familial peripheral neuropathy Charcot-Marie-Tooth disease, Type I (HMSN I) is assigned to the proximal long arm of chromosome #1 within 10 centimorgans of the Duffy locus (FY) (Povey et al.Hum. Gene Map 8, 1985). We report on the location of the CMT I gene in 6 families by examination of the heteromorphic, CBG-positive Iqh region which intervenes between FY and the #1 centromere. At least 10 pairs of straight, flat, well-differentiated CBG-banded #1 leukocyte chromosomes were evaluated. The 1qh regions were interpreted as approximately equal or unequal in length. Lengths of 1qh were estimated by comparison to the short arm of chromosome #6. In Family A the 1qh regions could be distinguished in cells from an affected proband. Two affected daughters carried the proband's #1 chromosome with the larger qh. Two fetuses from one of them also carried the identifiable 1qh at amniocentesis. Each affected member of Family B in 3 generations was recognized blindly through an identifiable 1qh. Linkage of CMT I to FY was confirmatory in Family A, but not informative for Family B. Blind cytogenetic analysis of Families C and D are in progress. Since 1qh heteromorphism was not present in 2 other CMT I family probands, these families were not further studied.
These data support assignment of CMT I gene to proximal 1g. Further, cytogenetic assessment of 1qh may provide information for counseling pre-symptomatic carriers and for prenatal diagnosis in affected CMT I families.
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Williams, L., Stallard, R. CHROMOSOMAL LOCATION OF THE CMT I GENE BY CBG-BANDING. Pediatr Res 21 (Suppl 4), 295 (1987). https://doi.org/10.1203/00006450-198704010-00769
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DOI: https://doi.org/10.1203/00006450-198704010-00769