​Pathology- Patau Syndrome and the Edwards Syndrome

​Pathology- Patau Syndrome and the Edwards Syndrome
Etiology 
Trisomy 18 is the primary cause of Edwards syndrome, typically resulting from meiotic nondisjunction. Maternal age increases the incidence. A few cases are due to mosaicism, which is the outcome of chromosome 18's nondisjunction during mitosis during embryogenesis.

Trisomy 13 is the primary cause of Patau syndrome, typically resulting from meiotic nondisjunction.
Maternal age increases the incidence. A small number of cases are due to mosaicism, which is brought on by translocation between chromosomes 13 and 14 or mitotic nondisjunction of chr 13 during embryogenesis.

Edwards syndrome is characterized by a severe developmental delay, feet that rock back and forth, broad occiput, low-set ears, micrognathia (small jaw), congenital heart and renal abnormalities, and overlapping third and fourth fingers.

Microcephaly and holoprosencephaly, cleft lip and palate, microphthalmia (small eyes), polydactyly, congenital cardiac and kidney abnormalities, umbilical hernia, and rocker-bottom feet are all symptoms of Patau syndrome.

The Patau and Edwards syndromes are fatal during the first year of life.

Patau Syndrome