SCIENTIFIC BACKGROUND

CFTR

SCIENTIFIC BACKGROUND

Congenital bilateral aplasia of the vas deferens (CBAVD) causes male infertility and may occur in isolation or as a manifestation of cystic fibrosis (CF). Obstruction of the vas deferens, due to degenerative changes, is responsible for infertility. CBAVD is understood to be an atypical, monosymptomatic form of CF and is grouped under CFTR-associated disorders (CFTR-RD). Here, pathogenic alterations in the CFTR gene lead to dysfunction of a chloride channel in the apical cell membrane of glandular epithelial cells and ultimately to alteration of the salt content of sweat and other body secretions.

 

The heterozygote frequency for pathogenic CFTR variants is estimated to be 1:25 in the Caucasian population. However, the spectrum of pathogenic variants differs from that of CF. In 40-50% of Caucasian CBAVD patients, at least one of the following three pathogenic alterations in the CFTR gene is detectable: p.(Phe508del), p.(Arg117His), 5T allele. Typically, CBAVD is a combination of one "severe" (e.g., p.(Phe508del)) and one "mild" CFTR variant (e.g., p.(Arg117His)) or two "mild" CFTR variants. Even if only one pathogenic alteration is detectable, it is still assumed that there's a second alteration not detectable with current testing methods. It is recommended to examine the partner of a CFTR carrier for pathogenic changes in the CFTR gene before a planned artificial insemination (ICSI). If a pathogenic CFTR variant is detected in both partners, the joint offspring has a 25% risk of having CF, and therefore, genetic counseling is recommended.

 

References

de Souza et al. 2018, Andrology 6: 127-135 / Yu et al. 2012, Hum Reprod 27: 25-35 / Gallati et al. 2009, Reprod Biomed Online 19: 5 / Claustres 2005, Reprod Biomed Online 10: 14 / Groman et al. 2004, Am J Hum Genet 74: 176-9

GENES

CFTR

ASSOCIATED TESTS

How to order

LATEST ARTICLES

Cystic fibrosis (CF) is a life-threatening, progressive, inherited condition that causes severe damage to the body, primarily affecting the organs of...

Read more

Down syndrome is a genetic condition caused by the presence of an extra copy of chromosome 21. It affects physical growth, facial features, and cogni...

Read more

Every year on April 25th, DNA Day celebrates the discovery of DNA’s double helix and the advances we’ve made in understanding genetics. D...

Read more

Neurodevelopmental disorders (NDDs) have diverse genetic origins, making diagnosis challenging. A new study analyzing over 1,100 pediatric patients f...

Read more

Colorectal cancer (CRC) remains one of the most prevalent and deadly cancers worldwide, with a significant number of cases presenting at an advanced ...

Read more

Carrier screening is a genetic test designed to identify whether an individual carries a gene with changes (mutations) associated with inherited diso...

Read more

Trisomy 13, also known as Patau syndrome, is a genetic condition in which cells in the body have three copies of chromosome 13 instead of two. The co...

Read more

The human brain develops through a complex series of events, with genes carefully regulating the formation of neurons and glial cells. A recent study...

Read more

Rare diseases affect between 300 and 400 million people worldwide – more than cancer and AIDS combined [1, 2], but despite this, many people face a...

Read more

Rosalind Elsie Franklin was a brilliant and meticulous research scientist whose interdisciplinary work made fundamental contributions to various area...

Read more