Question

Mongolism, Patau’s syndrome and Edward’s syndrome are due to
(a) Autosomal abnormalities
(b) Autosomal abnormalities
(c) Both A and B
(c) None of these.

Answer 1

Hint: The disruption in the normal chromosomal content of the cell. This originates as a result os an error during meiosis especially in the anaphase stage to chromosome which is not associated with the sex of the person.

Complete step by step answer:
Patau’s syndrome is caused by a chromosome abnormality, an extra copy of chromosome 13 also known as trisomy 13 or trisomy D.The trisomy 18 syndrome, also known as Edwards syndrome which is a common autosomal chromosomal disorder with the presence of an extra chromosome 18.
- Down syndrome
- This is typically associated with physical growth delays, characteristic facial features and mild to moderate intellectual disability indicates trisomy of 21.
- Trisomy 21 is caused by a meiotic nondisjunction event where a gamete is produced with an extra copy of the chromosome of 21, the gamete thus has 24 chromosomes. When combined with a normal gamete from the other parent, the embryo now has 47 copies with three copies of chromosome 21.
- Patau’s syndrome
- Patau’s syndrome or trisomy 13 is caused by nondisjunction of chromosomes during meiosis.
- In patau syndrome, the cells have three copies of chromosome 13 instead of the normal two copies where one copy is from maternal and the other one from paternal, also extra material from the extra chromosome attached to another chromosome.
- Edward’s syndrome
- Trisomy is the second most common autosomal trisomy syndrome after trisomy syndrome after trisomy 21.
- Edward syndrome is an autosomal chromosomal condition associated with abnormalities in many parts of the body as it is the result of having three copies of chromosome 18 instead of the usual two copies.
So, the correct answer is, ‘autosomal abnormalities.’

Note:
- Down syndrome is one of the most common chromosome abnormalities named after John Langdon Down, the British doctor who fully described the syndrome.
- Patau syndrome or trisomy 13 as it was first called was first observed by Thomas Bartholin in 1657 but the cause that is actually genetic and chromosomal- related parts of it were discovered by Dr, Klaus Patau in hence the name as Patau syndrome.
- The extra chromosome is present because of nondisjunction named after John H.Edward who first described Edward syndrome in 1960.