Mod 14

These flashcards cover key concepts, definitions, and classifications related to genetic and congenital counseling, screening, and testing as presented in Module 14.

What is Trisomy?

A genetic condition characterized by having an extra chromosome.

What are Monosomy and its implication?

Monosomy is a genetic condition where a chromosome is missing.

Define Nuchal tube defects (NTD).

Complex group of disorders caused by multiple genetic and environmental factors, occurring in the first four weeks of pregnancy.

What is Aneuploidy?

A genetic condition where a cell has an incorrect number of chromosomes.

What characterizes Trisomy 18 (Edward's Syndrome)?

Severe intellectual disabilities, congenital heart disease, and low-set ears.

What is Trisomy 21 also known as?

Down syndrome, characterized by an extra copy of chromosome 21.

What does DIA stand for?

Dimeric inhibin A, a protein produced by the placenta.

What is uE3?

Unconjugated estriol, a hormone produced by the placenta during pregnancy used in screenings.

What does Carrier screening allow for?

It allows individuals and couples to determine if they are carriers of genetic conditions?

What type of genetic disorders are Monogenic Disorders?

Disorders caused by mutations in a single gene.

What is consanguinity?

The characteristic of being descended from the same ancestor as another person, increasing risks for autosomal recessive disorders.

What does Meiosis refer to in genetics?

The process of making sex cells.

What is 1st trimester screening for Aneuploidy?

Test performed between 11-13 weeks of gestation to assess risk of chromosomal abnormalities.

What is measured in Nuchal Translucency ultrasound?

The thickness of the nuchal area as an independent risk factor for aneuploidy.

What is the purpose of the Quad Screen?

To screen for NTDs, Trisomy 18 & 21, with improved detection rates.

What is the Integrated Screening for Aneuploidy?

Combines 1st-trimester NT measurement and serum testing with 2nd-trimester quad screen.

What characteristics define Tay Sachs Disease?

A brain and nervous system disease that leads to progressive weakness and death by about 3–5 years.

What is the main risk factor for Down Syndrome?

Increased maternal age.

What are soft markers observed in ultrasounds?

Indicators, like short femur or increased NT, that suggest increased risk for aneuploidy.

What is Amniocentesis?

A diagnostic procedure used to obtain a sample of amniotic fluid for chromosomal analysis.

What is the significance of Cell-free DNA testing?

A non-invasive prenatal screening with high specificity for Down syndrome and other trisomies.

Define Fragile X Syndrome.

An X-linked disorder characterized by intellectual disabilities and developmental delays.

What are the challenges posed by ethical considerations in genetic counseling?

They include informed consent, bias, racism, and discrimination impacting genetic screening and healthcare outcomes.