TRISOMY 18

small chin

prominient occiput

rocker bottom feet

heart defects

failure to thrive- wont eat

profoundmental retardation

hypertonicity=clencedfinger

inc: 1:8k female

most die in 1 year (mostly die in tern)

maternal age effect

Trisomoy 13

sloping forehad/ forebrain defects

cleft lip and palate

plydactyl

heart defects

profound mental retardation

some translocation/mosaic

1:20k both sexes

most die in 1st year or dont make it to term

45 x (monosomy X)

short

under/degen ovaries

missing 2nd sex charac

broad and wide spaced nipples

NORMAL IQ

webbed skin fold at neck -birth

nuchal translucency

complications: 30: heart and renal/ 99% dont make it to term

Treatment: estrogen @ 12-->2nd sex charact

controversial-GH

if virilization: some of a Y maybe present: remove gonads

INC: 1/25-50k

30-40% mosaic ie 45X/46XX or 45x/46xy

NO maternal age effect

inclusion of cells originating from 2 digg zygotes

ie 2 fetuses sharing same blood supply

cells from one fetus go to other

can have male and female cells in blood

gonads have 2 diff groups of cells

ie 46 XY/ 46XXY or 45XX t(^%^)/46XX

2 cells groups w/ diff sex groups

1-2% of germlone mosaicism if both parents dont have it.--> say they had one kid who did

occurs in mitosis

inclusion of 2 diff types of cells in cell tissue.

47 XXY

Usually when men seek help with infertility

delayed social or developmental issues

more than average length, limbs

small testis

produce less testosteron

reduced sexual function

55% gynexomastia

Cause: 55% extra maternal X

46% paternal X

15% Mosaic

Complication: normal to mental retardation

obeisity, diabetes, pulmonary disaease, thyroid.

small tetsis--> less testosterone-->inc pit relase of gonadotrophion due to lack of feed back inh

treatment: androgen--> stimulates inc testosteron-->improves virlization, gynecomastica may worsen

normal to slight mental retard

each additional x-->inc mental retard

and formation of bar bodies

taller than average

cause: maternal age

1:1k females

tall

increased social problems

deletion in p arm of chrom 5

distinctive cry

10% from balance reciprocal translocation carriers

mostly spontaneous

low birth weight

most severly retarded

psychomotor retardation

microencphaly

distinct trinagluar head

may involve many genes, more=<retardation

incd:1/20-50k

1in100 severely retarded patients

Catch 22/ variable del of chrom 22q11(around 34 genes del)

aortic defects

hypothroid-->hyocalcemia

red immun

high risk of psychiatry disease

90% show missing areas in fish analysis

highly variable phenotype

label DNA with 2 blue probes to make sure right chromosome is tagged

ADD 2 diff color probes

if missing one color u know del in a gene

very specific... used to det if a gene is missing or not

diff color prbed for each chromosome

used to see if translocation has occured or trisomies

poor at finding deletions or duplications

used to diagnose trisomies

if 3 dots present=trisomy

very specific

fast, dont have to wait for metaphase chromosome

attach probes to slide

add patient's DNA

analyze

see how many copies u have

more expensive but better finding than fish

Philly chromosome

BCR-ABL is hallmark

Phiilly chrom t(9;22) q34:11.2)

ABL should not be there... codes for a signal transduction protein--> over prod of wbc

enlarged SPEEN --> bone marrow failure--> infections

often fatigue, night sweats and low grade fever

Treatment:tyrosine kinase inhb bcr-abl gene

one marrow translat only cure

SRY= master control for sex det

deletion in SOX9 or AR gene leads to 46 XY female phentoype

Intersex

presence of testes and ovarian tissue

usually 46XX w/ have SRY

also mosaics of 46 XX and 46XY

testis with streak of ovary

virilzation at puberty

must be a mosaic of 46XX 46XY, otherwise its turner

A: Prenatal exposure to androgen or progesteron

B. def in 11 or 21 hydroxylase

Hyperplasia of adrena cortex

2/3 have hyponatremia and hypekalemia if lack 21

males will have enlarged penis/ toddler can go through puberty

femal will only have ovaries and virilized

hirutism

lack of 21 more serious

95% 21

Normal: pit releases ACTH-->cholesterol->progestin->mineralocorticoids, androgens, or corticosteroids=neg inhibit pit

Abnormal. the lack of 21 or 11 hydroxylase prevents formation of mineralocorticoids and corticosteroids. so pit continously produces ACTH and there too much androgen synthesized.

Treatment with exogenous cortisol

lack of 21=MOST common

jews get 11