KaryotypingKaryotyping

Karyotyping TechniquesKaryotyping Techniques::

1) 1) Chorionic Villus Sampling (CVS)Chorionic Villus Sampling (CVS) – – performed at 8 to 10 weeks performed at 8 to 10 weeks gestation.gestation.

2) 2) AmniocentesisAmniocentesis – performed at 14 – performed at 14 to 16 weeks gestationto 16 weeks gestation

Some disorders checked for by amniocentesis are:

UltrasoundUltrasound

Amniocentesis

Process used to grow the baby’s cells

Chromosomes are arranged in size order # 1 Chromosomes are arranged in size order # 1 to 22 followed by the sex chromosomes(#23)to 22 followed by the sex chromosomes(#23)

Karyotype 1

DescriptionDescription of Karyotype 1 of Karyotype 1

GenderGender: Female: Female

# of Chromosomes# of Chromosomes: 46: 46

DisorderDisorder: No: No

Karyotype 2Karyotype 2Three

chromosomes at one spot

(instead of 2) is called

TRISOMY.

This karyotype is showing

TRISOMY 21 aka Down’s Syndrome

Description of Karyotype 2Description of Karyotype 2

GenderGender: Female: Female # of Chromosomes# of Chromosomes: 47: 47 DisorderDisorder: Trisomy 21 : Trisomy 21 a.k.a. a.k.a.

Down’s SyndromeDown’s Syndrome Unfortunately, it’s the most common Unfortunately, it’s the most common

trisomy disorder.trisomy disorder.

What is Down’s Syndrome?What is Down’s Syndrome?Down syndrome •some degree of mental retardation •characteristic facial features. •Sometimes have congenital heart defects•Many have some visual and hearing impairment.•The severity varies greatly.

Karyotype 3Karyotype 3

DescriptionDescription of Karyotype 3 of Karyotype 3

GenderGender: Male: Male# of Chromosomes# of Chromosomes: 47: 47DisorderDisorder: Trisomy 18 : Trisomy 18 a.k.a. Edward’s syndromea.k.a. Edward’s syndrome

Rick Santorum (republican candidate) and his daughter, Isabella, who has Trisomy 18

What is Edward’s Syndrome?What is Edward’s Syndrome?

Trisomy 18 is usually fatal*, with most Trisomy 18 is usually fatal*, with most of the babies dying before birth and of the babies dying before birth and those who do make it to birth typically those who do make it to birth typically living only a few days. However, a living only a few days. However, a small number of babies (<10%) live at small number of babies (<10%) live at least one year.least one year.

* characteristics include* characteristics include: a hole between the upper and/or lower : a hole between the upper and/or lower chambers of the heart, a narrowing of the exit vessel from the chambers of the heart, a narrowing of the exit vessel from the heart, kidney abnormalities, a portion of the intestinal tract can be heart, kidney abnormalities, a portion of the intestinal tract can be located outside the stomach in a sac, the esophagus does not located outside the stomach in a sac, the esophagus does not connect to the stomach, meaning the baby cannot eat by mouth, connect to the stomach, meaning the baby cannot eat by mouth, clenched hands, rocker bottom feet, small jaw, and developmental clenched hands, rocker bottom feet, small jaw, and developmental delays.delays.

Karyotype 4

Description of Karyotype 4Description of Karyotype 4

Gender: FemaleGender: Female # of Chromosomes: 45# of Chromosomes: 45 Disorder: Disorder: Turner’s SyndromeTurner’s Syndrome (only 1 (only 1

X)X)

Turner’s SyndromeTurner’s Syndrome

Absent or incomplete development at Absent or incomplete development at puberty, including sparse pubic hair puberty, including sparse pubic hair and small breasts and small breasts

Broad, flat chest shaped like a shield Broad, flat chest shaped like a shield Drooping eyelids and dry eyes Drooping eyelids and dry eyes Possible Infertility Possible Infertility No periods (absent menstruation) No periods (absent menstruation) Short height Short height

Karyotype 5Karyotype 5

Description of Karyotype 5Description of Karyotype 5

Gender: maleGender: male # of Chromosomes: 47# of Chromosomes: 47 Disorder: Disorder:

– Klinefelter’s SyndromeKlinefelter’s Syndrome

Klinefelter’sKlinefelter’s

low levels of the hormone testosteronelow levels of the hormone testosterone beginning beginning during puberty. during puberty.

Possible breast developmentPossible breast development (gynecomastia), (gynecomastia), reduced facial and body hairreduced facial and body hair Possible infertilityPossible infertility Female fat distribution (wide hips)Female fat distribution (wide hips)

Photo of Photo of Klinefelter’s Klinefelter’s SyndromeSyndrome

Karyotype 6Karyotype 6

Karyotype 6Karyotype 6

Gender: FemaleGender: Female

# of Chromosomes: 47# of Chromosomes: 47

Disorder: yesDisorder: yes

Trisomy 13: Patau SyndromeTrisomy 13: Patau Syndrome

Trisomy 13: Patau SyndromeTrisomy 13: Patau Syndrome PolydactylPolydactyl Cleft palateCleft palate Mental Mental

retardationretardation 90 -95% die 90 -95% die

within the within the first yearfirst year

HermaphroditeHermaphrodite

Genetically XX XYGenetically XX XY 48 Chromosomes48 Chromosomes Has both female and male genitalia.Has both female and male genitalia. extremely rareextremely rare