PATHO 13

congenital defect

present at birth or shortly after

causes of congenital defects

1. gentic factors (gene mutations)

2. environmental factors during embryonic or fetal development (maternal desiese or drugs taken during pregnency)

3. rarely intrauterine factors (fetal crowding, entangelment with umbillical cord)

genetic defect

defect passed from one generation to another by genes

single gene disorder

caused by a defect in one gene

they are inhereted

chromosomal disorder

error during meiosis

cause of spontaneous abortion

multifactorial disorder

not just genitic - can be caused by multiple genes or inherited with envirnmental factors

punnet squares

predicts the percent chance of offspring to carry the genetic defect or suffer from the deffect

autosomal recessive disorder

both parents must pass on the allele for disorder

homozygous

either RR or rr u have the trait

hetrozygous

Hh ur just a carrier - no signs of deseise

single gene disorders are classified by…

punnet squares

autosomal dominant dsorders

inheritance if one allele causes disorder; only one parent need to carry allele - NO CARRIERS SO HETROXYGOUS CHILD IS ALSO AFFECTED

X-Linked recessive disorders

allele on x chromosome but not on Y

in hetrozygous males lacking the matching gene on the Y chromozome

so it affects males - they cant be carries they either have it or dont

X-Linked dominent disorders

hetrozygous male and female are affectes

reduced penetrance in females

tetratogenic agent

environmental agent that produces abnormalities during embryonic or fetal development

organogeneis

a teratogenic agent that affects organ development

what are TORCH infections

drugs or infectious agents impacting fetus

what can developmental disorders develop from

1. teratogenic agents

2. premature birth

3. difficult delivery

who should be tested fo congenital and geneitc disorders

• family history of disease
• previous child with abnormality
• pregnant women over 35

method of prenatal testing

1. chorionic villus sampelinf

2. pubs - blood smaple

3. cell free dna - alos blood test