Patau's syndrome diagnosis

By Dr Joe Kabyemela, MD

Patau syndrome is ‘Trisomy 13’. This means the affected fetus has an extra chromosome at pair number 13. The occurrence is 1 in 5 to 6 thousand live births.

Prenatal diagnosis of Patau syndrome

The screening blood tests for Down's can help detect Patau's syndrome as well. In addition, a detailed ultrasound has a good chance of detecting the various physical and organic defects associated with Patau's. The scan findings may therefore trigger a definitive diagnostic test. Physical and organic defects found in Patau syndrome include:

Ø A small head (microcephaly)

Ø Increased number of fingers and/or toes (polydactyly)

Ø Cleft palate and/or cleft lip (‘hare-lip’)

Ø Heart defects normally atrial septal defects (ASD)

Ø Brain and spinal defects such as holoprocsencephaly and meningomyelocele

Ø Abdominal wall defect (omphalocele) with intestines outside the abdominal cavity

Long-term prospects for a Patau's syndrome baby

These children have such severe physical and mental handicaps that the majority of children with Patau’s syndrome die before the age of two. Less than 3% survive to the age of three and virtually none reach five years of age.

Apart from the obvious developmental delays, the child may be blind and deaf.

Other chromosomal disorders

There are hundreds of different chromosomal disorders. Some of the chromosomal disorders are so lethal that pregnancies never advance beyond the first 8 - 10 weeks. Those pregnancies will be characterized by early miscarriage. Miscarriage is usually not recurrent unless one of the parents is a carrier of the defect.

Other chromosomal disorders may be compatible with life, albeit short, but are very rare.

Curing a chromosomal disorder

A chromosomal make-up of an individual is determined at conception. This cannot be altered afterwards. It is therefore not possible to ‘cure’ any chromosomal disorder, nor is there any prospect of this being feasible in the foreseeable future.