genetic diseases

what % of congenital defects are of unknown causes

75%

what % of congenital defects are caused by genetics

20%

what does congenital defect mean

defect that is present at birth

types of exogenous teratogens

physical, chemical, microbial

types of physical teratogens

x-rays, corpuscular radiation

types of chemical teratogens

industrial chemicals, drugs, alcohol

microbial teratogens

viruses, bacteria, protozoal parasites (ex: herpes virus, histoplasmosis)

types of structural chromosomal abnormalities

deletion and translocation

what is a deletion chromosomal abnormality

loss of a portion of the chromosome

what is a translocation chromosomal abnormality

movement of part of 1 chromosome to another chromosome

what is down syndrome

trisomy 21

what is the most common numerical abnormality of autosomes

down syndrome

symptoms of down syndrome

intellectual disability, unique facial features, eye abnormalities, gaping mouth and large tongues, heart diseases (cardiomyopathy, congestive heart failure), intestinal defects (IBS-chrons), hand and toes abnormalities

what is turners syndrome

XO

what is klinefelters syndrome

XXY

what meiotic problem gives rise to turners syndrome and klinefelters syndrome

a nondisjunction of the female gamete during the first meiotic division

what are the most common serious numerical defects of sex chromosomes

turners syndrome and klinefelters syndrome

symptoms of turners syndrome

short stature, heart shaped face, webbing of neck, heart disease, broad chest, cubitus valgus, streak ovaries, hypoplastic uterus, amenorrhea, infertile

symptoms of klinefelter syndrome

tall, long arms and legs, lack of beard/body hair/pubic hair, gynecomastia (breast development in males), female like hips, testicular atrophy, small external genitals, infertility (normally not a problem before puberty but is a problem after)

what type of mendelian inheritance is super rare bc it would be very quickly removed from the gene pool

sex linked dominant

what tissue is affected in marfans syndrome and what kind of mendelian inherited disorder is it

connective tissue, autosomal dom

what tissue is affected in wilms syndrome and what kind of mendelian inherited disorder is it

kidney, autosomal dom

what tissue is affected in huntingtons disease syndrome and what kind of mendelian inherited disorder is it

nervous system, autosomal dom

what tissue is affected in neurofibromatosis syndrome and what kind of mendelian inherited disorder is it

nervous system, autosomal dom

symptoms of marfan syndrome

elongated head, eye problems (cataracts, blindness), aortic aneurysm (weakness of vessels and floppy valves), lose mitral value, vertebral deformity, long fingers

examples of autosomal recessive disorders

cystic fibrosis, sickle cell anemia, thalassemia, phenylketonuria

what tissues are affected in cystic fibrosis

pancreas, intestines, bronchi

what does a positive sweat test mean

cystic fibrosis

wht is the most common autosomal recessive disorder in the us

cystic fibrosis

what is cystic fibrosis

defect in cystic fibrosis conductins regulator protein → make too little NaCl in all exocrine gland secretions → secretions are more thick → leads to malabsorption, bronchitis, recurrent pneumonia and eventually death

symptoms of cystic fibrosis

salty sweat, constant pneumonia, fat in feces, chronic pancreatitis, inadequate respiration, often die young

if you cant make any tyrosine, what can you not produce

melanin, dopamine, and some proteins

what kind of disorder is phenylketonuria

an amino acid metabolism disorder that is autosomal recessive

what happens in phenylketonuria

body cant make good phenylketonuria, which is needed to metabolize phenyalalnine (consumed in dietary protein) into tyrosine → instead get build up of phenylpyruvic acid which is toxic and inadequate tyrosine

symptoms of phenylketonuria

fair skin, mousy odor, severe loss of mental function if untreated

how is phenylketonuria treated

a low phenylalanine diet and a tyrosine supplement

why could phenylketonuria be a problem in pregnant women

if unmanaged (bc mental function no longer a concern bc their brain is already developed) even if it wouldnt affect the mom a ton any more the build up of phenylpyruvic acid would be toxic to the fetus and lead to maternal PKU

how do men with X linked recessive disorders pass those down

cant pass those traits to their sons (bc they give their sons their y chromosome) but all of their daughters will be carriers of the gene

examples of x linked recessive diseases

hemophilia A and B, muscular dystrophy, congenital immunodeficiencies, wiskott-aldrich syndrome

Hemophilia a and b are examples of

x linked recessive disorders

what clotting factor is deficient in hemophilia A

factor 8

what clotting factor is deficient in hemophilia B

factor 9

another name for hemophilia B

christmas disease

which hemophilia is more common

A, by a lot

what accounts for 90-95% of severe congenital coagulation factor deficiencies

hemophilia A and B

what can mild hemophilia B be treated w

vitamin K supplements

what percent of hemophilia A pts have the severe form

50%

what is multifactorial inheritance

inheritance of a trait or disorder that is influenced by genetics (often multiple genes) as well as environmental/exogenous factors

what is an example of a multifactoral metabolic disorder

type 2 diabetes