Birth Defects

Question 0

Axenfeld-Rieger syndrome

Answer 0

Mutations in single genes (PITX2, FOXC1) alter development of multiple systems

Eye disorder but affects other parts of body like dental and facial

Question 1

Birth defects

Answer 1

Can be congenital malformation (structural, functional or behavioral disorder present at birth)

Caused by genetic problems, environmental, multifactorial, twinning

Question 2

Holoproscencephaly

Answer 2

Gene-gene and gene-environment interactions determine disease severity

Malformation of forebrain (failure to divide) from chromosome abnormalities, environmental conditions (maternal diabetes), single gene mutation (genes operate in hedgehog signaling pathway)

Question 3

Infectious agents can cause birth defects

Answer 3

Rubella virus during pregnancy causes congenital rubella syndrome

Question 4

Pharmacological agents can cause birth defects

Answer 4

Thalidomide used to treat nausea in pregnant women causes limb defects

Question 5

Teratology

Answer 5

Study of birth defects

Question 6

Teratogen

Answer 6

Agents that cause birth defects

Susceptibility to teratogens depends on developmental stage at time of exposure (3-8 weeks), dose and duration of exposure, genotype of embryo/mother, gene-environment interactions

Question 7

Fetal alcohol syndrome

Answer 7

Small head size, congenital mental retardation from alcohol (environment), is most serious type of feral alcohol spectrum disorder (FASD)

Question 8

Antidepressants

Answer 8

Can cause birth defects

Selective serotonin reuptake inhibitors (SSRIs)

Heart defects, persistent pulmonary hypotension, neural tube defects, cleft lip, autism, etc.

Question 9

Congenital heart defects

Answer 9

Most common birth defect, broad range of severity, altered by teratogens, chromosome abnormalities, multifactorial causes, changes route of blood flow

Signs and symptoms include rapid breathing, cyanosis, fatigue, poor blood circulation

Question 10

Atrial septal defect (ASD)

Ventricular septal defect (VSD)

Answer 10

Opening in wall of left and right atria

Hole in septum between ventricles

Question 11

Heterotaxy

Answer 11

Laterality defects, heart malformations

Dextrocardia: heart on right side, if situs inversus totalis, then fine but if heterotaxy then results heart malformations like Septal defects, double outlet right ventricle, transposition of the great arteries

Question 12

22q11.2 deletion syndrome

Answer 12

Heterogenous multi system syndrome, 3 million base pair deletion on chr 22, congenital heart disease, heart malformations include:

Tetralogy of Fallot-VSD, pulmonary stenosis (narrowing of pulmonary valve and artery), overriding aorta (increases flow), ventricular hyper trophy

Truncus arteriosus-outflow tract defects where only one common blood vessels comes out of heart not usual main pulmonary artery and aorta (gene affected that usually regulate cardiac neural crest cells migrating from dorsal neural tube into arterial pole to separate outflow tract)