Men with a genetic variant on the Y chromosome are NINE times more likely to have fertility problems

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Men with a genetic variant on the Y chromosome are NINE times more likely to have fertility problems, study warns

  • Male infertility is estimated to be around 10 percent of men in the UK
  • But for about 60 percent of these men, the cause remains unclear
  • Scientists studied the genomes of 2,300 men in Estonia, half of whom had fertility problems
  • Some men carried a genetic variant on the Y chromosome, which affects the area known to be important for sperm development
  • Monitoring the genetic variant could help identify men at higher risk early

It’s a problem that affects about 10 percent of men in the UK, but the cause of about 60 percent of male infertility cases remains unknown.

Now scientists have discovered a genetic variant on the Y chromosome that significantly increases the risk of infertility problems in men.

The variant appears to affect the region of the Y chromosome that is important for sperm development.

The researchers hope that monitoring the genetic variant can help identify men at higher risk in their early adulthood, enabling them to make more informed decisions about future family planning.

Scientists have discovered a genetic variant on the Y chromosome that significantly increases the risk of infertility problems in men (stock image)

Scientists have discovered a genetic variant on the Y chromosome that significantly increases the risk of infertility problems in men (stock image)

The Y chromosome

Human body cells have 23 pairs of chromosomes in the nucleus.

Twenty-two couples control most of the features, while pair 23 are the sex chromosomes.

They carry genes that determine the sex of an embryo – whether the offspring are male or female.

Males have two different sex chromosomes, XY

Females have two X chromosomes, XX

In the study, researchers from the Wellcome Sanger Institute and the University of Tartu conducted the largest genetic study to date on unexplained infertility in men.

More than 2,300 men from Estonia were recruited for that study – about half of whom had unexplained fertility problems.

An analysis of their genomes revealed that some of these men carried a genetic variant on the Y chromosome, with an inversion in the region known to be important for sperm development (spermatogenesis).

While the inversion itself does not appear to have a direct effect on fertility, it does increase the likelihood of the carrier deleting this portion of the Y chromosome genetically.

A deletion can increase the risk of a low or even non-existent sperm count nine times, according to the researchers.

The reversal alone is relatively common and can be passed from father to son, and is found in a ‘significant number’ of men of European descent.

Dr. Pille Hallast, co-author and Senior Staff Scientist at the University of Tartu and the Wellcome Sanger Institute, said: ‘Our study is the largest, most advanced look at the genetic variation of this particular Y chromosomal region that can increase the risk. increase decreased sperm production in men.

The researchers hope that monitoring the genetic variant can help identify men at higher risk in their early adulthood, enabling them to make more informed decisions about future family planning (stock image)

The researchers hope that monitoring the genetic variant can help identify men at higher risk in their early adulthood, enabling them to make more informed decisions about future family planning (stock image)

The researchers hope that monitoring the genetic variant can help identify men at higher risk in their early adulthood, enabling them to make more informed decisions about future family planning (stock image)

By having access to such a large number of patients and reference men, and by being able to compare their genetic data with andrological information, we have identified a common Y chromosome subtype that is susceptible to genetic changes leading to a low sperm count, but that too can go unnoticed and pass in families until a deletion occurs in this genomic region. ‘

The team hopes their findings could lead to screening for this subtype, inversion, and deletion to help men understand the root cause of any fertility problems.

Professor Maris Laan, senior co-author and professor of human genetics at the Institute of Biomedicine and Translational Medicine, University of Tartu, Estonia, said: ‘Being able to identify the genetic reason why these men have decreased sperm production will help them diagnose and access to the support that this entails.

Although it was previously known that some deletions on the Y chromosome disrupted sperm production, understanding at this level of detail is important for the management of male fertility problems, and in this case the possibilities of having children early in life or saving sperm for later . use is negotiable. ‘

In the UK, it is estimated that infertility affects up to one in seven heterosexual couples.

The NHS explained, “There are many possible causes of infertility, and fertility problems can affect both partners. But in a quarter of the cases the cause cannot be determined. ‘

THE CAUSES OF MALE Infertility

The most common cause of infertility in men is poor quality semen, the fluid that contains semen that is ejaculated during sex.

Possible reasons for abnormal semen include:

  • a lack of semen – you may have a very low sperm count or no semen at all
  • sperm that are not moving properly – this makes it more difficult for sperm to swim to the egg
  • abnormal sperm – sperm can sometimes have an abnormal shape, making it more difficult for them to move and fertilize an egg

Many cases of abnormal semen are unexplained.

There is a link between elevated scrotal temperature and reduced sperm quality, but it is uncertain whether wearing loose-fitting underwear improves fertility.

Testicles

The testicles produce and store sperm. If they are damaged, it can seriously affect the quality of your semen.

This can happen as a result of:

  • an infection of your testicles
  • testicular cancer
  • testicular surgery
  • a problem with your testicles that you were born with (a birth defect)
  • when one or both testicles have not descended into the scrotum, the loose sac of skin that contains your testicles (undescended testicles)
  • injury to your testicles

Sterilization

Some men choose to have a vasectomy if they no longer want children or children.

It involves cutting and sealing the tubes that carry sperm from your testicles (the vas deferens) so that your sperm no longer contains sperm.

A vasectomy can be reversed, but reversals are usually unsuccessful.

Hypogonadism

Hypogonadism is an abnormally low level of testosterone, the male sex hormone involved in making sperm.

It can be caused by a tumor, taking illegal drugs, or Klinefelter syndrome, a rare syndrome in which a man is born with an extra female chromosome.

Medicines and medicines

Certain types of drugs can sometimes cause infertility problems.

These drugs are listed below:

  • sulfasalazine – an anti-inflammatory medicine used to treat conditions such as Crohn’s disease and rheumatoid arthritis sulfasalazine can decrease sperm count, but the effects are temporary and your sperm count should return to normal when you stop taking it
  • anabolic steroids – often used illegally to build muscle and improve athletic performance; Long-term abuse of anabolic steroids can decrease sperm count and sperm mobility
  • chemotherapy – drugs used in chemotherapy can sometimes severely reduce sperm production
  • herbal remedies – some herbal remedies, such as root extracts from the Chinese herb Tripterygium wilfordii, can affect sperm production or reduce the size of your testicles
  • illegal drugs, such as marijuana and cocaine, can also affect sperm quality.

Source: NHS

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