This document discusses different types of autosomal aneuploidy including Down's syndrome, Edward's syndrome, and Patau's syndrome. Autosomal aneuploidy occurs when there are missing or extra autosomal chromosomes 1-22. It can be caused by errors in cell division such as non-disjunction or spindle assembly disruption. The most common trisomies seen in live births are of chromosomes 21, 18, and 13, which cause Down's syndrome, Edward's syndrome, and Patau's syndrome respectively. Each syndrome is associated with specific physical characteristics and health issues.

1. AUTOSOMAL ANEUPLOIDY
DOWN’S SYNDROME
EDWARD’S SYNDROME
PATAU’S SYNDROME

2. AUTOSOMAL ANEUPLOIDY
▪ When any of the individual autosomal chromosome are
missing or extra .
▪ Can happen to all of the autosomal chromosomes (1-22)
▪ 2N-1 = monosomy
▪ 2N+1= trisomy
▪ 2N-2 = nullisomy
▪ 2N+2= tetrasomy

3. WHAT CAUSES IT ?
Errors during cell division
▪ Non dys-junction
▪ Spindle assembly disruption (SAC Defects)
▪ Deletion
▪ Translocation

4. RESULTS OF AUTOSOMAL ANEUPLOIDY
Most cases of aneuploidy in
the germline result in
miscarriage, and the most
common extra autosomal
chromosomes among live
births are 21, 18 and 13.
▪ Second bullet point here
▪ Third bullet point here
▪ DOWN’s syndrome
(trisomy 21)
▪ EDWARD’s syndrome
(trisomy 18 )
▪ PATAU syndrome
(trisomy 13)

5. DOWN’S SYNDROME
Chromosomal complement:
47,XX,+21 (female)
47,XY,+21 (male)
-Nondisjunction
-Robertsonian translocation
-mosaicism

6. APPEARENCE
*Short height
*Severe mental deficiency with
decline in the IQ with age
*Brachycephaly with flat face and
occiput
*Flat and low nasal bridge
*Upward slant to palpebral fissures
*Malformed large ears
*Prominent and protruding tongue
(scrotal tongue)

7. Associated with:
*Congenital heart disease
*Acute myeloid leukemia
*Acute lymphoblastic leukemia
*Alzheimer’s
Hirschsprung’s disease

8. EDWARD SYNDROME
Chromosomal complement:
47,XX,+18 (female) or
47,XY,+18 (male)
-Nondisjunction

9. *Mental deficiency
*Growth retardation
*Prominent occiput with
elongated head
*Webbing of the neck
*Short sternum
Micrognathia
Features of Edward Syndrome

10. *Low-set malformed
ears
*Ventricular septal
defects
*Renal anomalies
*Clenched fists with
overlapping of fingers
*Hypoplastic nails

11. PATAU SYNDROME
1st described by Bartholin (1657) &
redefined by Patau (1960).
47,XX,+13 (female)
47,XY,+13 (male)
- Nondisjunction

12. *Microencephaly
*Low birth weight
*Holoprosencephaly
*Absence of corpus callosum
*Hypoplasia of cerebellum
*Scalp defects
Patau syndrome

13. *Malformed ears
*Congenital heart defects
*Renal tract anomalies
*Microphthalmia
*Bilateral cleft lip/palate
*Polydactyly
*Rocker-bottom heel