Genes and Genetic Disorders of the Y Chromosome

Flashcards covering key terms and concepts discussed in the lecture.

Testis Determining Factor (TDF)

The all-important gene that triggers male development, initially identified through karyotyping in the 1950s.

Linkage Mapping (Positional Cloning)

A method used to identify genes by observing the co-segregation of traits with markers in families.

Deletion Mapping

An alternative approach to gene mapping used in the absence of recombination, involving the examination of chromosomes with translocations to determine the smallest region containing a gene of interest.

SRY Gene

The gene identified through deletion mapping as the testis-determining factor, containing a DNA binding domain and acting as a master switch.

SOX Family

A family of genes related to SRY, encoding diverse regulators of development, including SOX9, which is also involved in sex determination.

SOX9

A gene located on the long arm of chromosome 17 that is upregulated by SRY and orchestrates a cascade of gene interactions leading to testis formation.

Androgen Insensitivity Syndrome

A syndrome in females caused by mutations in the androgen receptor gene on the X chromosome, preventing cells from responding to androgen.

Congenital Adrenal Hyperplasia

A condition resulting from mutations on an autosomal gene causing overproduction of androgens from the adrenal glands, leading to a male phenotype in XX individuals.

Hairy Ears

A Y-linked trait that was considered a textbook example, involving hairs growing from the margin of the ear, but is now debated.

Azoospermia Factor (AZF)

A condition identified in infertile men, associated with deletions in specific regions of the Y chromosome.

Genomic Disorders

Recurrent but independent mutations arising in different families as a consequence of the same underlying structural basis, such as highly similar repeats.

Paralogues or Segmental Duplications

Highly similar repeats within the genome that can misalign and cause non-allelic homologous recombination, leading to deletions, duplications, or inversions.

AZFA Region

A region on the Y chromosome associated with infertility, deletion of which is often the result of aberrant recombination between HERV elements.

The longer and more similar the repeats, the more likely they are to misalign and cause rearrangements.

General rule in genomic disorders