Genetics: Patau Syndrome

Question 1

Patau syndrome is a chromosomal disorder where there is an extra copy of chromosome…

Answer 1

13

Question 2

What is another name for it?

Answer 2

Trisomy 13

Question 3

Is it a common trisomy?

Answer 3

No - not as common as Down syndrome or Edwards syndrome

It is the most severe

Question 4

What process accounts for most of the cases?

Answer 4

Nondisjunction

Question 5

What less common process can account for the condition?

Answer 5

Robertsonian translocation

Question 6

Do multiple organ defects occur?

Answer 6

Yes as the extra chromosome causes over expression of all genes on the chromosome - this disrupts normal development

Question 7

What defects can occur?

Answer 7

Microcephaly
Structural brain defects
Meningomyelocele (severe spina bifida)
Scalp defects
Small eyes 
Polydactyly 
Cleft lip and palate 
Severe intellectual disability 
GI - omphalocele 
Heart problems 
Renal - PCKD

Question 8

What risk factors are there ?

Answer 8

Advancing maternal age

FH

Question 9

Do most babies with Patau’s syndrome die before birth?

Answer 9

Yes

Question 10

What is the median survival time?

Answer 10

3 days

Question 11

What is cutis aplasia ?

Answer 11

Failure of skin to develop in certain areas e.g on scalp

Question 12

What is microthalmia?

Answer 12

Small eyes

Question 13

What severe defects can occur?

Answer 13

Cyclopia

Nose may be missing