1. Chromosomal disorders (syndromes)

2. Syndrome
A syndrome is a group of symptoms with a single underlying cause
Several syndromes result from nondisjunction which is the failure of chromosomes to separate properly during meiosis
The resulting egg or sperm will carry an unusual number of chromosomes

3. Down’s Syndrome
Trisomy 21 (nondisjunction of the 21st chromosome) = 47 chromosomes overall
Characteristics
Short stature
Mentally challenged
Deformed hearts
Abnormal eyelids
Large tongues

4. Klinefelter’s Syndrome
Nondisjunction of sex chromosomes ending up with XXY
Characteristics
Sexually immature
Males develop large breasts
High pitched voice
Low intelligence
Look stretched
Y chromosome = male

5. Turner’s Syndrome
Nondisjunction of sex chromosomes resulting in X (45 chromosomes)
Characteristics
Shorter, stockier girls
Large necks
Sexually immature

6. Super Male Syndrome
Nondisjunction of sex chromosomes ending up with XYY
Characteristics
More aggressive
Tall
Acne

7. Cri-du-chat syndrome Results from missing a part of the 5th chromosome
Characteristics
Moon shaped face
Cat-like cry
Small head
Wide set eyes
Abnormal or low ears
Mental retardation

8. Human Karyotype