Suggest why sex chromosome aneuploids are more common in hum

Suggest why sex chromosome aneuploids are more common in humans than autosomal aneuploids. (In other words, suggest why humans are more tolerant of abnormal numbers of sex chromosomes compared to abnormal numbers of autosomes.)

Solution

Answer:

Humans are more tolerant of abnormal number of sex chromosomes (sex chromosome aneuploidy) compared to abnormal numbers of autosomes because of the below reason there is already a pre-existing mechanism to compensate for additional X chromosome in female somatic cells - by X-chromosome inactivation. Inactivation of one X chromosome in females helps in gene dosage compensation and equalizes gene expression between the sexes. On the other hand autosomal aneuploidy is in general more lethal and results in the death of the developing fetus.