One form with the 5T allele is usually found in CF, whereas the 7T allele is often seen in CBAVD and 9T is usually not disease causing.
The subsequent identification of another mutation is consistent with a diagnosis of azoospermia due to CBAVD, if the two mutations were inherited on different chromosomes.
2] Nonstandard abbreviations: CF, cystic fibrosis; CBAVD
, congenital bilateral absence of the vas deferens; ACMG, American College of Medical Genetics; ACOG, American College of Obstetricians and Gynecologists.
diagnosis of CBAVD
which may affect the reproductive future of siblings).
Our data confirm the high frequency of 5T-12TG in CBAVD patients and do not preclude an effect in pancreatitis as well.
Prevalence of the 5T allele and the 5T-poly(TG) haplotypes in CBAVD patients, pancreatitis patients, and individuals undergoing ART.
Whereas homozygosity for the [DELTA]F508 mutation will cause CF, double heterozygosity for the F508C mutation, in combination with either the [DELTA]F508 or [DELTA]I507 mutation, may cause CBAVD
While most patients with CBAVD
do not have clinical CF,[sup.
patients carry either a CF mutation ([DELTA]F508 in 16-83% of cases and R117H in 6-29% of cases) and/or a 5T variant in intron 8 (12-47% of patients), supporting the hypothesis that CBAVD
represents a mild, primary genital form of CF (2-7).
There are three main molecular scenarios that are clinically relevant: (a) When 5T is present with a severe CF mutation on the opposite chromosome (in trans), individuals may be asymptomatic, may have mild symptoms of CF, or if male, may have CBAVD
The realization that CFTR gene mutations are a prominent molecular basis of isolated CBAVD
led to the discovery that many of these men exhibit subtle, CF-like, sinopulmonary abnormalities not reported in their initial urological review.
Among the 19 CBAVD
subjects investigated (of the 38 chromosomes analyzed), 8 (21%) carry the 5T variant, 19 (50%) the 7T variant, and 11 (29%) the 9T variant.