A routine genetic screen using cell-free DNA—a highly accurate blood test—suggested her fetus had an extra copy of chromosome 13 (Patau syndrome) and only one copy of chromosome 18.

At 13 weeks and 6 days, it can be up to 2.8 mm. If your baby’s measurements are within this range, they have a low chance of having Down syndrome or other genetic disorders.

Each chromosome has a short and a long arm. Chromosomes 13, 14, 15, 21, and 22 have a very short arm, which doesn’t contain any unique genetic material, and are called acrocentric chromosomes.

Patau’s Syndrome is also known as Trisomy 13. It is a chromosome-based, rare genetic disorder in which the patient has an extra copy of chromosome 13 in some or all of the cells in the body ...

Patau’s syndrome, also referred to as Trisomy 13, is a chromosome-based, rare genetic disorder in which the some or all of a patients cell contain an extra copy of chromosome 13. Normally a baby ...

Chromosomal abnormalities are differences in the chromosomes that can happen during embryonic and fetal development. They could be "de novo" (unique to the fetus) or inherited from a parent.

The American Academy of Pediatrics has released new guidance stating that the genetic disorders Trisomy 13 and 18 are not ...

Cells that were obviously disrupted or in which the chromosomes were poorly spread were not counted. Analysis of 34 cells demonstrated an extra acrocentric chromosome in Group 13–15 (Fig. 4).

Abnormal Karyotypes and Subtypes of 13–15 Complements (Type C). An assumed total chromosome number of 45 was found in the maternal grandfather, 2 great-aunts, 1 aunt and the index patient (Table 1).