Developmental disorders

Question 1

Most common form of Down syndrome

Answer 1

Complete trisomy 21

Question 2

Two more uncommon forms of Down syndrome

Answer 2

Translocation Down syndrome

Mosaic Down syndrome

Question 3

Percentage of Down syndrome caused by full trisomy 21

Answer 3

95%

Question 4

Percentage of Down syndrome caused by translocation

Answer 4

2-3%

Question 5

Percentage of Down syndrome caused by mosaicism

Answer 5

2-3%

Question 6

Risk of Down syndrome with a maternal age of 35

Answer 6

1 in 385

Question 7

Risk of Down syndrome with maternal age of 40

Answer 7

1 in 106

Question 8

Risk of Down syndrome with maternal age 45

Answer 8

1 in 30

Question 9

Type of Down syndrome which is inherited

Answer 9

Translocation

Question 10

Type of Down syndrome which occurs as a random event during early foetal development

Answer 10

Mosaic

Question 11

Type of Down syndrome caused by non-disjunction, with the extra chromosome coming most often from the mother but also can be from the father

Answer 11

Full trisomy

Question 12

Typical facial features of Down syndrome

Answer 12

Small mouth and protruding tongue
Flat occiput
Small low-set ears
Upward slanting eyes
Epicanthic folds
Small, flat nose

Question 13

Non-facial physical features of Down syndrome

Answer 13

Single palmar crease
Sandal gap between toes
Hypotonia
Low birth weight
Short stature
Overweight as an adult

Question 14

Most common cardiac defect associated with Down syndrome

Answer 14

AVSD

Question 15

Medical comorbidities associated with Down syndrome

Answer 15

Visual problems
Ear infections
Leukaemia
Obesity
Underactive thyroid
Diabetes
Reduced fertility
Early onset Dementia
Oesophageal atresia
Hirschsprung's disease

Question 16

Tests used to assess for dementia in patients with Down syndrome

Answer 16

DMR (Dementia questionnaire for persons with mental retardation)
DSDS (Dementia scale for Down Syndrome)

Question 17

Condition usually seen in adolescent boys characterised by increased need for sleep, tendency to eat any food available and emotional and behavioural problems

Answer 17

Kleine-Levin syndrome

Question 18

Usual timing of symptoms in Kleine-Levin syndrome

Answer 18

Abrupt onset
Symptoms remain for a few days
Abrupt disappearance
Repeated episodes like this that can last years, often with a gradual decrease in severity

Question 19

Condition characterised by neurological and behavioural difficulties in conjunction with overproduction of uric acid

Answer 19

Lesch-Nyan syndrome

Question 20

Most distinctive behavioural problem associated with Lesch-Nyan syndrome

Answer 20

Self-injury including biting

Question 21

Gene responsible for Lesch-Nyan syndrome

Answer 21

HPRT1

Question 22

Enzyme deficiency seen in Lesch-Nyan syndrome

Answer 22

Hypoxanthine phosphoribosyltransferase 1

Question 23

Sex almost exclusively affected by Rett syndrome

Answer 23

Females

Question 24

Gene responsible for Rett syndrome

Answer 24

MECP2 gene

Question 25

Age at which children with Rett syndrome stop developing at a normal rate

Answer 25

6-18 months

Question 26

Common features of Rett syndrome

Answer 26

``` Loss of language skills Seizures Stereotypic movements e.g. hand wringing Microcephaly Breathing problems Loss of motor function ```

Question 27

Risk of Turner syndrome in siblings of those with Turner syndrome

Answer 27

Unchanged from baseline risk

Question 28

Features of Turner syndrome

Answer 28

``` Short stature Webbed neck Broad chest Infertility (usually but not always) Congenital heart disease Hypothyroidism ```