Chromosomes Karyotypes 1 Chromosome Number All cells in

Chromosomes & Karyotypes 1

Chromosome Number All cells in the human body (SOMATIC CELLS) have 46 chromosomes or 23 pairs GAMETES (eggs & sperm) have only 23 chromosomes Karyotype – organized profile of a person’s chromosomes Arranged and numbered by size, from largest to smallest 2

Normal Male copyright cmassengale 2 n = 46 3

Normal Female copyright cmassengale 2 n = 46 4

Chromosomal Disorders Deletion Inversion Translocation Non-disjunction 5

Chromosomal Deletion Part of a chromosome is missing due to breakage 6

Cri-Du-Chat Syndrome 1 in 216, 000 births 46 chromosomes #5 Deletion of lower arm : s m o ce a pt f m d y e S p a h s Moon disease d t e Hear lly retard x a n Ment med lary r Malfo l lifespan a Norm

Aniridia-Wilms Tumor Syndrome ths 1 0 bir 0 0 , 0 0 0 in 50, mes o m o 46 chr X XY or X pper u f o n o i et #11 Del arm ms: ded o t p Sym lly retar a d Ment h retarde t Grow ess eys n n d d n i i l k B on s r o Tum lifespan t Shor

Thirteen Q Deletion Syndrome 1 in irths b 0 0 500, 0 mes o rom 46 ch X r. X XY o arm r e w of lo n o i t ele #13 D Mentally retarded Deformed face No thumbs Heart disease Short lifespan

Chromosomal Inversion During meiosis, a segment of the chromosome breaks off, flips upside down and reattaches itself 10

Four-Ring Syndrome 1 in 10, 000 births 46 chromosomes XY or XX #4 Inversion late a p t nd e Clef feet c s de Club s don’t n te Tes lifespa rt Sho

Chromosomal Translocation Occurs when a piece of one chromosome breaks off and attaches to another 12

Burkitt Lymphoma Translocation of the Myc gene on chromosome 8 Normal Myc genes control cell growth and division • Translocated Myc genes don’t function properly • Leads to cancer of the lymph nodes

Chromosomal Nondisjunction When cells go through meiosis, the chromosomes don’t separate correctly and either too many or not enough are passed on. 14

Turners Syndrome 1 in 5, 000 births 45 chromosomes X only #23 Monosomy Nondisjunction 96 -98% do not survive to birth No menstruation No breast development Narrow hips Broad shoulders and neck

Down Syndrome: Trisomy 21 1 in 1, 250 births 47 chromosomes XY or XX #21 Trisomy Nondisjunction nds a h d broa s , t r o Sh ger n i f y b Stub skin les h a g m u o R cy in ed n e t o Imp lly retard e a Ment round fac e u ll Sma ding tong u Protr lifespan t Shor

Klinefelter Syndrome 1 in 1, 100 births 47 chromosomes XXY only #23 Trisomy Nondisjunction ard arms e d b n a ce Scar r fingers e Long ile Ster te skin lity i a Delic ental ab n m Low al lifespa Norm

Patau’s Trisomy Syndrome 1 in 14, 000 births 47 chromosomes XY or XX #13 Trisomy Nondisjunction yes ad e e h g l l in Sma or miss ll Sma defects rt Hea fingers talia i a Extr rmal gen ed d o rth i Abn lly retar b r ta afte s k Men palate e we t w f e e f l C ea i d t Mos

Jacob’s Syndrome 1 in 1, 800 births 47 chromosomes XYY only #23 Trisomy Nondisjunction ? Normal physically Normal mentally Increase in testosterone More aggressive Normal lifespan