Childhood syndromes

Question 1

Describe the defect and clinical features in Patau Syndrome

Answer 1

Trisomy 13

Question 2

Describe the defect and clinical features of Edward’s Syndrome

Answer 2

Trisomy 18

Question 3

Describe the defect and clinical features of Fragile X syndrome

Answer 3

CGG trinucleotide repeat in FMR1 gene on X chromosome

Impaired intellectual development

Autism, ADHD

Question 4

Describe the defect and clinical features of Noonan Syndrome

Answer 4

Autosomal dominant defect in one of several genes

Pulmonary valve stenosis, ASD, HCM

Question 5

Describe the defect and clinical features of Pierre-Robin syndrome

Answer 5

Unknown aetiology

Micrognathia

Posteriorly displaced tongue

Cleft lip/palate

Question 6

Describe the defect and clinical features of Prader-Willi Syndrome

Answer 6

Paternal chromosome 15q partial deletion

Hypotonia

Hypogonadism

Obesity

Question 7

Describe the defect and clinical features of William’s Syndrome

Answer 7

Chromosome 7q deletion

Short stature

Learning difficulties

Friendly, extroverted

Supravalvular aortic stenosis

Transient neonatal hypercalcaemia

Question 8

Describe the defect, clinical features and diagnosis of phenylketonuria (PKU)

Answer 8

Autosomal recessive defect in phenylalanine hydroxylase gene in most cases - responsible for conversion of phenylalanine to tyrosine.

Occasionally due to defect in dihydropterin reductase enzyme which produces the necessary conversion cofactor tetrahydrobiopterin.

Patients usually present by 6 months with developmental delay.

Fair hair, blue eyes; learning difficulties; seizures; eczema; musty smell to sweat and urine.

Guthrie test; hyperphenylalaninaemia; phenylpyruvic acid in urine.

Question 9

Describe the defect and clinical features of Down Syndrome

Answer 9

Trisomy 21