FINAL - CH 15 Flashcards
Common Indications for Genetics Referral
Intellectual disability or developmental delay
Single or multiple malformations; question of a dysmorphic syndrome
Possible inherited metabolic disease
Presence of a possible single-gene disorder
Presence of a chromosomal disorder, including balanced translocation
Presymptomatic screening (e.g Huntington’s, various cancers)
History of recurrent miscarriages
Consanquinity in a couple (generally first cousins or closer)
Teratogen counseling
Advanced maternal age
Steps for Bayes theory
Prior probability
Conditional probability
Joint probability
Posterior probability
Prior probability
1/2
Conditional probability
1/2 ^(how many kids)
Joint probability
Prior prob x conditional prob
Posterior probability
Divide the joint prob by sum of the two joint probs
If individual has another child whats the prob they WILL inherit the disease?
Posterior probability x 1/2
Malformations
morphologic defect of an organ or body part resulting from an abnormal developmental process
Ex: cleft lip, polydactyly
Important to determine etiology of the malformation in order to determine recurrence risk
Causes of Malformations
Chromosomal abnormalities Single mutant genes Multifactorial inheritance Teratogens Uterine factors Unknown causes
oligohydramnios
reduced amount of amniotic fluid
Causes for oligohydramnios
Bilateral renal agenesis
Polycystic kidneys (type 1)
Urethral obstruction
Chronic leakage of amniotic fluid
Teratogens
An agent external to the fetus’s genome that induces structural malformations, growth deficiency, and/or functional alterations during prenatal development.
Importance of teratogens
can be preventable and thereby reduce birth defect burden
