tetratology and clinical chemistry Flashcards
Lab tests can be used for:
Diagnosis Prognosis Treatment Screening Research into biochemical basis of disease Clinical trial of new drugs
Plasma =
Blood with all cells removed
Serum =
Blood with cells and coagulation proteins removed
Biological testing can be divided into 2 groups:
- Selective requesting
2. Screening
Selective requesting =
Carried out on basis of individual patient’s clinical situation
Screening tests =
Look for disease without there being a necessary clinical indiciation
Newborn screening progaramme looks for how many conditions?
9
Conditions looked for in newborn screening program:
Sickle cell disease Cystic fibrosis Congenital hypothyroidism Phenylketonuria Medium-chain acyl-CoA dehydrogenase deficiency Maple syrup urine sidase Isovaleric acidaemia Glutaric aciduria type 1 Homocystinuria
PKU is the absence of =
Phenylalanine hydroxylase
Test for PKU
Guthrie test
Background risk of congenital defects =
2-3%
Teratogens can induce =
Chromosomal abnormalities Structural abnormalities Impairment of implantation Abortion Fetal death IUGR Functional impairment Behavioural problems Mental retardation
Ex of teratogens:
Medicines Chemicals Radiation Infection Maternal metabolic disorder
Birth defects seen in T21 =
Mental retardation Muscle weakness Downward slant of eyes Misformed, lowset ears Abnormal crease in palm of hand Heart and intestine defects
Defects seen in turner’s syndrome =
Short stature
No ovaries
Learning disabilities
Teratogen =
Agent that, if administered to pregnant mother, causes structural or functional abonormalities in foetus.
Behavioural teratology =
Effects behaviour or functional adaptation of the offspring to its environment
FAS symptoms =
IUGR
Behaviour issues
Learning difficulities
Facial dysmorphia: low nasal bridge, flat midface, thin upper lip, small chin
No adverse effects on mother but cancer in offspring =
Transplacental carcinogenicity
Ex of drug that has transplacental carcinogenicity
Diethysiboestrol Synthetic oestrogen (vaginal)
General principles of teratogens:
May be harmless to mother Time of exposure important Duration and dose important Genetically determined susceptibility Synergistic Placental barrier doesn't exist
Mendelial inheritence and defects =
Single gene, recognisable patterns, risk to future babies doesn’t change
Ex of monogenic problems =
CF, sickle cell, Marfan’s, DMD
Multifactoral inheritience =
Multiple genes and environment.
Risk changes
