Embryology and Genetics of Hearing

These flashcards cover key concepts in embryology and genetics of hearing as discussed in the lecture notes.

What is Deoxyribonucleic acid (DNA) composed of?

Base chemical units: Adenine, thymine, guanine, cytosine.

What matches with adenine in DNA pairing?

Thymine matches with adenine.

What does C match with in DNA pairing?

Cytosine matches with guanine.

What is a genome?

Total composition of genetic material in a cell, packaged into chromosomes.

How many pairs of chromosomes do humans have?

23 pairs of chromosomes.

What are autosomes?

22 pairs of chromosomes (1-22) that are not sex chromosomes.

What is the mutation in genetics?

A 'misspelling' of a single base in the DNA.

What does deletion in genetic mutations refer to?

Loss of a single or multiple base pairs.

What is a karyotype?

A complete chromosome set containing 46 chromosomes.

What is the difference between syndromic and non-syndromic hearing loss?

Syndromic hearing loss has additional clinical features; non-syndromic does not.

What percentage of hearing loss cases are syndromic?

30-40% of cases of hearing loss.

What is an example of syndromic hearing loss?

Associated with anomalies like eye, kidney, or musculoskeletal features.

What does autosomal recessive inheritance pattern represent?

Both parents are carriers, but do not show the condition.

What is the probability of children having a condition with autosomal recessive inheritance?

25% chance of having the condition.

What characterizes autosomal dominant inheritance?

One parent has the condition, with a 50% chance for children to inherit it.

What is the key feature of X-lined recessive inheritance?

Mother can be a carrier; sons can inherit the condition from their mother.

What does mitochondrial inheritance signify?

Only females can pass on mitochondrial conditions; it can be seen in every generation.

What are DFNA and DFNB classifications?

DFNA indicates autosomal dominant, DFNB indicates autosomal recessive.

What is Connexin 26?

A mutation in the GJB2 gene, causing half of hereditary SNHL cases.

What causes aminoglycoside induced hearing loss?

Mitochondrial inheritance leading to predisposition from aminoglycoside antibiotics.

What is Waardenburg syndrome?

An autosomal dominant disorder causing pigmentation issues and hearing loss.

What is Pendred syndrome known for?

The most common cause of autosomal recessive syndromic hearing loss, often including enlarged vestibular aqueduct.

What does Branchio-Oto-Renal (BOR) syndrome affect?

Developmental disruption of neck tissues, ear malformations, and kidney issues.

What is CHARGE syndrome associated with?

Coloboma, heart anomalies, choanal atresia, growth retardation, genital abnormalities, and ear issues.

What is Alport syndrome primarily characterized by?

X-linked inheritance, leading to progressive kidney failure and hearing loss.

What does Jervell and Lange-Nielsen syndrome involve?

Congenital SNHL and arrhythmia.

What is Stickler syndrome?

A genetic disorder with variable inheritance affecting eyes, musculoskeletal structures, and hearing.

What is Treacher Collins syndrome?

An autosomal dominant condition impacting facial bone development, often with hearing loss.