Congenital bilateral aplasia of the vas deferens

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Classification according to ICD-10
Q55.4 Other congenital malformations of the ductus deferens, the epididymis, the vesiculae seminales and the prostate
ICD-10 online (WHO version 2019)

A congenital bilateral absence of the vas deferens ( CBAVD , Engl. Congenital bilateral aplasia of vas deferens for, congenital sided absence of the vas deferens ' and shortly also CAVD for congenital aplasia of vas deferens ) may be isolated or as a mild form of cystic fibrosis occur. The disease is autosomal - recessive inherited and by a mutation in CFTR causes gene. In contrast to the classic form of cystic fibrosis, the clinical picture of CBAVD is mostly limited to a lack of the vas deferens. In patients with CBAVD, the formation of sperm cells in the testes is normal. However, since the sperm ducts are missing, the sperm cells formed in the testes can only get into the epididymis and not further outside.

root cause

With CAVD, a distinction can be made between a bilateral (CBAVD) and a unilateral (CUAVD) form based on the number of defective vas deferens. Congenital unilateral or bilateral aplasia is based on a mutation in the CFTR gene ( cystic fibrosis transmembrane conductance regulator ) in 75–90% of cases . People with such a mutation usually have a mild form of cystic fibrosis, in which only the vas deferens is affected. Whether a mutation leads to cystic fibrosis or CAVD depends on the severity of the mutation in both alleles.

Pathogenesis

It is not yet known how a CFTR mutation leads to the absence of the vas deferens. A spermatic duct disorder is believed to be caused during fetal development. In the examined fetuses with CFTR mutation from the 12th and 18th week of pregnancy, however, no abnormalities with regard to the spermatic duct were found. Therefore, a blockage of the ducts by viscous secretions is more likely the cause.

reproduction

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Those affected with genital cystic fibrosis are carriers of the classic form. Your offspring have an increased risk of developing cystic fibrosis. Therefore, the partner should be tested for a possible CFTR mutation. If the test is negative, there is a residual risk, as only the most common mutations are tested and the test sensitivity is only 90%.

Clinical diagnostics

A CAVD can be detected with the help of a semen examination. The CFTR mutation removes water from the secretions due to the osmotic effect. As a result, the sperm of CAVD patients has a lower pH value , less volume and a lower fructose content compared to normal seminal fluid .

treatment

Surgical treatment is not possible. A desire to have children can be fulfilled through artificial insemination ( intracytoplasmic sperm injection ).

literature

  • M. Claustres: Molecular pathology of the CFTR locus in male infertility. In: Reproductive biomedicine online. Volume 10, Number 1, January 2005, pp. 14-41, ISSN  1472-6483 . PMID 15705292 . (Review).
  • H. Cuppens, JJ Cassiman: CFTR mutations and polymorphisms in male infertility. In: International journal of andrology. Volume 27, Number 5, October 2004, pp. 251-256, ISSN  0105-6263 . doi : 10.1111 / j.1365-2605.2004.00485.x . PMID 15379964 . (Review).
  • G. Phillipson: Cystic fibrosis and reproduction. In: Reproduction, fertility, and development. Volume 10, Number 1, 1998, pp. 113-119, ISSN  1031-3613 . PMID 9727601 . (Review).
  • WB Guggino, BA Stanton: New insights into cystic fibrosis: molecular switches that regulate CFTR. In: Nature reviews. Molecular cell biology. Volume 7, Number 6, June 2006, pp. 426-436, ISSN  1471-0072 . doi : 10.1038 / nrm1949 . PMID 16723978 .
  • T. Dörk, B. Dworniczak, C. Aulehla-Scholz, D. Wieczorek, I. Böhm, A. Mayerova, HH Seydewitz, E. Nieschlag, D. Meschede, J. Horst, HJ Pander, H. Sperling, F. Ratjen, E. Passarge, J. Schmidtke, M. Stuhrmann: Distinct spectrum of CFTR gene mutations in congenital absence of vas deferens . In: Human genetics , Volume 100, Numbers 3-4, September 1997, pp. 365-377. doi : 10.1007 / s004390050518 . PMID 9272157

Web links

Congenital bilateral aplasia of the vas deferens.  In: Online Mendelian Inheritance in Man . (English)

Individual evidence

  1. ↑ Alphabetical index for the ICD-10-WHO version 2019, volume 3. German Institute for Medical Documentation and Information (DIMDI), Cologne, 2019, p. 263