Cytogenetics in Medicine - Practice Flashcards

A collection of Q&A flashcards covering cytogenetics concepts, techniques, disorders, inheritance patterns, and examples from the notes.

What is the main goal of cytogenetics in medicine?

To analyze chromosomes to diagnose diseases, guide treatment, and monitor prognosis using techniques such as karyotyping, FISH, CGH, and molecular cytogenetics.

What is a genetic disorder?

A condition caused by a mutation in a gene or by an abnormal amount of genetic material in chromosomes.

How can genetics affect human health?

Genetics influence disease risk, presentation, progression, and response to therapy; disorders can be chromosomal, multifactorial, or monogenic.

Name the major categories of genetic diseases.

Chromosomal disorders, multifactorial (complex) disorders, and single gene (monogenic) disorders.

What are the key approaches in cytogenetic analysis?

Chromosome analysis (karyotyping), fluorescent in situ hybridization FISH, and genomic microarray analysis; molecular cytogenetics is an extension.

Describe chromosome analysis (karyotyping).

Examines stained chromosomes arranged in a standard order to detect numerical or structural abnormalities.

What abnormalities can karyotyping reveal?

Aneuploidy such as Down syndrome and structural changes like translocations, deletions, and inversions.

What is FISH and what can it detect?

Fluorescence in situ hybridization uses fluorescent DNA probes to detect chromosomal abnormalities at higher resolution, including deletions, duplications, translocations, and gene copy number changes.

What is Genomic Microarray Analysis?

A high throughput method to detect copy number variations across the genome, including small CNVs not visible by karyotype or FISH.

What is Molecular Cytogenetics?

A field combining cytogenetics with molecular biology using technologies like high throughput sequencing and next generation sequencing to understand disease and guide targeted therapies.

What is Constitutional cytogenetics?

Focuses on inherited genetic abnormalities, used in prenatal diagnosis, pediatric cases, or developmental issues.

What is Cancer cytogenetics?

Investigates acquired somatic genetic changes in cancer cells for diagnosis, prognosis, and treatment monitoring.

What are Chromosomal disorders?

Disorders involving numerical or structural abnormalities of chromosomes.

What are Numerical Abnormalities (Aneuploidy)?

Abnormal chromosome number, such as monosomy or trisomy; examples include Down syndrome, Turner syndrome, and Klinefelter syndrome.

What is Monosomy?

Loss of one chromosome from a pair, resulting in 45 chromosomes.

What is Trisomy?

An extra chromosome, resulting in 47 chromosomes.

What is Polyploidy?

More than two complete sets of chromosomes, such as triploidy or tetraploidy.

What are Autopolyploids?

Polyploids with multiple chromosome sets from the same species.

What are Allopolyploids?

Polyploids with chromosome sets from different related species.

What mechanisms can lead to polyploidy?

Nondisjunction, hybridization, and mutations.

What are Multifactorial (complex) genetic disorders?

Disorders caused by a combination of gene mutations and environmental factors, often familial and not Mendelian.

Give examples of multifactorial disorders in congenital anomalies.

Neural tube defects such as spina bifida and cleft lip/palate.

Give examples of multifactorial disorders in chronic diseases.

Type 2 diabetes, heart disease, Alzheimer's disease, and some cancers.

Give examples of multifactorial disorders in neuropsychiatric conditions.

Autism spectrum disorder, schizophrenia, and bipolar disorder.

What are Single-gene (monogenic) disorders?

Disorders caused by mutations in a single gene; inherited or de novo, collectively significant in disease burden.

What are common inheritance patterns for monogenic disorders?

Autosomal dominant, autosomal recessive, and X linked.

What is autosomal dominant inheritance?

Only one copy of the mutated gene is needed for the disorder to manifest.

What is autosomal recessive inheritance?

Two copies of the mutated gene are needed for the disorder to manifest.

What is X linked inheritance?

Mutated gene on the X chromosome; inheritance risk differs between males and females.

Give examples of monogenic disorders and their inheritance patterns.

Cystic fibrosis (autosomal recessive); Sickle cell disease (autosomal recessive); Huntington disease (autosomal dominant); Duchenne muscular dystrophy (X linked recessive); Familial hypercholesterolemia (autosomal dominant).