Question

What are the main diseases caused by errors in the number of sex chromosomes in the cells of an individual?

Answer 1

The humans have two sex chromosomes X,Y females carry two copies of x chromosomes X X and males carry one of each XY.

Disorders of sex chromosomes abnormalities are

Delay of puberty

Primary or secondary amenorrhea

Infertility

Ambiguous genetalia

Klinefelter's syndrome: it is an XXY syndrome it is a syndrome where human males have extra X chromosomes.

Signs and symptoms:the phenotype of the effected person is male,tall stature with elongated lower legs and forearm the body shape is feminine with a lower muscle mass some individuals shows gyanaecomastia.

Fertility: the main symptom of this condition is infertility

IQ: can be reduced to 10-15 points

Turner's syndrome:it is characterised by 45 X karyotype in females with the absence of x chromosomes.

Short stature, infertility,average intelligence, cardiovascular abnormalities

Triple X syndrome:it may be caused due to errors in maternal meiosis 1.they have serious learning problems varitions include tetrosomy X syndrome,pentasomy.

XXY syndrome:it may be caused by paternal non disjunction at meiosis 2. They have these features,

Tall stature,severe acne, average intelligence,normal sexual development.