DHED 309: Genetic disorders A

A ______ is not a disease, but grouping of similar symptoms

Syndrome

Syndrome definition

association of sign/symptoms occurring together in a patient

Phenotype is a

physical, biochemical, physiologic make up of a perosn

Genotype is a

genetic composition of a person

Autosomes are

ONLY non-sex chromosomes

Autosome's are identical for

men and women

Dominant

trait that is always expressed

Recessive

trait that shows when double homozygous exists in chromosomes or single gene dose.

Females

XX

Males

XY

Homozygous

two genes that are the same

Heterozygous

Two different genes

Carrier

induvial who has a gene that is ressecive that they carry but you don't see (Not expressed) but can pass it on

X chromosomes carry

inherited traits

Y chromosomes only participate in

differentiation on masculine gonads

What are the letters for X-Linked Inheritance

and explain

x and y because, this is impacting the sex chromsomes

sometimes upper or lowercase, what matters is which is affected

What is the Autosomal inheritance letters look like

the same letters, but one is lower case and the upper case, or both

Clinical manifestations for Autosomal Dominant inheritance is

-Penetrance

-Expressivity

Penetrance is

= number of individuals affected

Lack of penetrance is

when person carries gene without any clinical manifestations

Expressivity is

degree to which a person is affected by trait/ gene

Autosomal recessive inheritances means

indivual showing trait must have BOTH homozygous (bb) for the gene

Autosomal Recessive inheritance (RISK TO Offspring ) is 25% IF (BB)

Both parent s are carries

Autosomal Recessive inheritance (RISK TO Offspring ) is 50% IF (Bb)

chance of offspring carrying trait not expressed

Autosomal Recessive inheritance (RISK TO Offspring ) is 100% IF (bb)

both parents have trait

X-linked inheritance means

trait is coming from female (can be recessive or dominant)

In a man a X-linked trait will be seen

regardless if its dominant or recessive

X-linked recessive traits are only seen in

males

"X-link inheritance" Risk to offspring if female is a carrier is

50% (no matter gender)

Trisomy 21 is

Down syndrome

A risk factor for Trisomy 21

Mothers high age at conception

Trisomy is descirbed as having

47 chromosomes

Clinical features of Down syndrome

-Flat face with up slanting eyes

-Mental retardation

-Thyroid disease

-Congenital heart defects

friendly dispositon

Oral features of Trisomy 21

macroglossia

fissured tongue

tooth malformation

hypodontia (↓ number of teeth)

periodontal disease (90%)

TX mods for Trisomy 21

frequent recall

Simian crease