CYTOGENETICS approaches to medicine

What are the main objectives of studying cytogenetics in medicine?

1. Survey the role of cytogenetics in medicine;

2. Define genetic disorder;

3. Explain how genetics affects health;

4. Identify major categories of genetic diseases;

5. Discuss important concepts in genetics;

6. Review ABC’s of genetics and genomics

Name three common techniques used in cytogenetic studies.

Karyotyping; G-banding; Fluorescence in situ hybridization (FISH)

What is the main advantage of cytogenetic analysis in oncology?

It helps identify chromosomal abnormalities to guide effective chemotherapy or targeted therapy.

List three key cytogenetic approaches used in clinical diagnosis.

Chromosome analysis (karyotyping); FISH; Genomic microarray analysis

Give two examples of new techniques in cytogenetics.

Spectral karyotyping; CRISPR genome editing

Define karyotyping.

A technique to examine stained chromosomes under a microscope, arranged in standard order to detect numerical and structural abnormalities.

What are examples of conditions diagnosed via karyotyping?

Down syndrome; Turner syndrome; Klinefelter syndrome

How does FISH work?

Uses fluorescent DNA probes to bind specific chromosome regions, allowing detection of small deletions, duplications, and translocations.

What does genomic microarray analysis detect?

Copy number variations (CNVs) across the genome.

What is molecular cytogenetics?

The combination of cytogenetics and molecular biology techniques (e.g., NGS) for deeper disease analysis and targeted therapies.

Differentiate constitutional cytogenetics from cancer cytogenetics.

Constitutional: inherited abnormalities; Cancer: acquired genetic changes in tumor cells.

What causes genetic disorders?

Mutations or abnormal amounts of genetic material affecting genes.

What are the two main types of chromosomal disorders?

Numerical abnormalities; Structural abnormalities.

Give an example of a monosomy.

Turner syndrome (45, X)

Give three examples of trisomies.

Down syndrome (21); Edward syndrome (18); Patau syndrome (13)

What is polyploidy?

A condition with more than two complete sets of chromosomes (e.g., triploidy = 69, tetraploidy = 92).

Differentiate autopolyploids from allopolyploids.

Autopolyploids: multiple chromosome sets from the same species; Allopolyploids: from different but related species.

Name three causes of polyploidy.

Nondisjunction; Hybridization; Mutations

What are complex (multifactorial) disorders?

Disorders caused by multiple genes and environmental factors.

Give three examples of multifactorial disorders.

Type 2 diabetes; Heart disease; Spina bifida

What is a monogenic disorder?

A condition caused by a mutation in a single gene.

List three inheritance patterns of monogenic disorders.

Autosomal dominant; Autosomal recessive; X-linked

Give one example of each inheritance pattern in monogenic disorders.

Autosomal dominant – Huntington’s disease; Autosomal recessive – Cystic fibrosis; X-linked – Duchenne muscular dystrophy

Why is gene therapy significant for monogenic disorders?

It offers potential to treat or cure diseases by fixing the faulty gene.