Patau syndrome, or chromosome 13 trisomy, is a complex of complex birth defects. The risk of this lethal genetic disease increases in women who have decided to give birth to a child after the age of 35 or 40. What are the causes and symptoms of Patau syndrome? What is the treatment of this type of disease? Is Patau syndrome hereditary?

Patau syndromeis a complex of complexbirth defects( lethal genetic defect syndrome ) the reason is the presence of an extra third copy of chromosome 13 in the DNA.Chromosome 13 trisomyis the rarest and most severe form of trisomy, diagnosed in 1: 8,000-12,000 babies born. Doctors' experience shows that it affects girls more often. Male fetuses usually do not live to birth.

Patau syndrome: causes

The discussedchromosomal aberrationmay be caused by incorrect and - what should be emphasized - spontaneous separation of homologous chromosomes (father and mother) in the process of generating reproductive cells. As a consequence, the whole tetrad goes to one of the gametes (it has one chromosome too many, i.e. n + 1), while no chromosome from this pair goes to the other.

The cause of the trisomy of the 13th chromosome can also be - belonging to the group of balanced translocations - which can be referred to when the chromosomes are rearranged, i.e. one chromosome from one pair is attached to a chromosome from another pair. Translocation can either be inherited from a parent or arise during fertilization.

Patau syndrome: symptoms

  • Prenatal symptoms

Patau syndrome can be diagnosed as early as the second trimester of pregnancy. Then, during the ultrasound examination, you can see, among others physical development retardation or microcephaly.

  • Postnatal symptoms

Patau syndromeis composed of several dozen different defects, therefore the most characteristic symptoms are listed belowsymptoms:

  • low birth weight
  • reduction of muscle tone
  • scalp skin defect
  • holoprosencephaly (incomplete division of the forebrain)
  • severe visual impairment (including cyclops - instead of two eyeballs there is one)
  • abnormally developed nose
  • cleft lip and / or palate
  • numerous defects of the auricles, e.g. low position
  • anomalies of the limbs (e.g. additional fingers or toes, positioning of the fingers in the shape of a "shotgun hammer", prominent heel);

In addition, you can diagnose heart and kidney defects, brain malformations and neural tube defects, cryptorchidism in boys, and uterine malformations in girls.

It should be noted that the above-mentioned abnormalities do not occur all at once, and the degree of their severity depends mainly on the type of genetic disorder (the presence of all or only part of an extra chromosome).

Patau team: diagnostics

  • Diagnostics in the prenatal period

The first examination during which Patau syndrome can be initially diagnosed is the above-mentioned Ultrasound. If the disease is suspected, the doctor may refer the patient to invasive prenatal tests, such as amniocentesis or chorionic villus sampling. Based on the collected cellular material, cytogenetic tests are performed, which can confirm the presence of the disease with 99% certainty.

  • Diagnostics after the birth of a child

After childbirth, genetic tests based on chromosome analysis are performed again for the final diagnosis.

Patau's team: prognosis

Due to coexistence of birth defects, most (estimated 80%) children with Patau syndrome die within days or weeks of birth. More than 90% do not live to the end of the first year of life, only about 5% of patients reach the age of three.

Patau syndrome: treatment

Due to the variety of symptoms, treatment depends on the child's he alth. Therefore, it may be necessary, for example, to have a split lip or cleft palate surgery or a heart defect. Physical therapy plays a huge role in symptomatic treatment.

Patau's team: risk factors

The risk of developing this genetic disease increases in women who have decided to give birth to a child after the age of 35 or 40.

Another factor that increases the risk of Patau syndrome is that one of the parents carries the translocation of the balanced chromosome of the 13th pair.

Is Patau syndrome hereditary?

Even if one of the parents carries an equivalent translocation - which is one of the causes of the trisomy of the 13th chromosome - the defective genes need not be passed on to the offspring.

There is also a possibilitythat the child will inherit the same balanced translocation as the parent, but will not experience any discomfort or will be born with a developmental delay (the risk is higher than average). It may also happen that the pregnancy ends in a miscarriage.

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Category:

Genetic diseases