Introduction to cytogenetics pdf

This article is about a type of chromosome. The members of introduction to cytogenetics pdf autosome pair in a diploid cell have the same morphology unlike those in allosome pairs which may have different structure.

Autosomes still contain sexual determination genes even though they are not sex chromosomes. For example, the SRY gene on the Y chromosome encodes the transcription factor TDF and is vital for male sex determination during development. The sex chromosomes are different: There are two copies of the X-chromosome in females, but males have a single X-chromosome and a Y-chromosome. An illustration of the inheritance pattern and phenotypic effects of an autosomal recessive gene.

Autosomal genetic disorders can arise due to a number of causes, some of the most common being nondisjunction in parental germ cells or Mendelian inheritance of deleterious alleles from parents. Autosomal aneuploidy can also result in disease conditions. Aneuploidy of autosomes is not well tolerated and usually results in miscarriage of the developing fetus. Partial aneuploidy can also occur as a result of unbalanced translocations during meiosis. Deletions of part of a chromosome cause partial monosomies, while duplications can cause partial trisomies.

If the duplication or deletion is large enough, it can be discovered by analyzing a karyogram of the individual. Campomelic dysplasia and autosomal sex reversal caused by mutations in an SRY-related gene. Maternal age-specific fetal loss rates in Down syndrome pregnancies”. Modeling the molecular consequences of unbalanced translocations in cancer: lessons from acute lymphoblastic leukemia”. 11 Translocation Provides the Best Evidence Supporting Genetic Etiology for Schizophrenia and Bipolar Affective Disorders”.