Chromosomal Alterations

Somatic Cells

Non-Sex Cells (Body Cells) (Dipliod Cells)

There are 46 chromosomes total (23 pairs)

Gametes

Sex Cells (23 chromosomes) (Haploid Cells)

Euploid cell

ones containing the expected number of chromosomes “healthy”

Autosomes

The first 22 pairs of chromosomes

Sex Chromosome

Last pair of chromosomes identify sex (XX-F) (XY-M)

Karotype

Order display of chromosomes

Aneuploidy

A somatic cell that does not contain a multiple of 23 chromosomes

Trisomy

Containing three copies of one chromosome

• Some varrites will result in live birth

Monosomy

Containing only one copy of a chromosome

• Often DO NOT result in live birth - miscarriage 99%

Disjunction

Normal seperation of chromosomes

Nondisjunction

Abnormal sepration of chromosomes

Trisomy can be caused by

Old maternal age (above 35)

Trisomy is usually

Down syndrome/Trisomy +21

Trisomy +21/ Down Syndrome Features include

• D = Developmental delay

• O = Oblique/upward eyes

• W = Weak muscle tone

• N = Neck short/flat facial profile

Trisomy X/ 47,XXX

Is when a female has an extra X chromosome present

Trisomy X/ 47,XXX features include

Height is greater than that of siblings and family

Slight language delay

No fertlity efftects

Klinefelters/ 47 XXY

Extra X chromosome on a male

Klienfelters features include

-Large beasts

-Small testes

-Tall and narrow

-Infertlity unknown

Monosomy X/45 X/ Turner Syndrome features include

- wide-neck (webbed)

-short

-sheild chest