Genetics

Question 1

What are the 8 congenital abnormalities?

Answer 1

Deformation
Dysplasia
Malformation
Disruption
Sequence
Syndrome
Association 
Dysmorphism

Question 2

What is a deformation?

Answer 2

Distortion of a structure by mechanical force e.g. club foot occurs in late pregnancy

Question 3

What is dysplasia?

Answer 3

Abnormal organisation of cells into tissue e.g. thanatophoric dysplasia which causes extremely short bones

Question 4

What is a malformation?

Answer 4

A primary structural defect e.g. cleft lip

Question 5

What is a disruption?

Answer 5

An extrinsic factor affecting normal development e.g. a digital amputation - genetic factors may predispose

Question 6

What is a sequence?

Answer 6

Multiple abnormalities initiated by a primary factor e.g. reduced amniotic fluid leads to Potter sequence

Question 7

What is a syndrome?

Answer 7

A consistent pattern of abnormalities e.g. Down’s syndrome

Question 8

What is association as a medical term?

Answer 8

Non-random occurrence of clinical features (not explained by sequence or syndrome) e.g. VACTRL (