Common Syndromes and their Recognition Flashcards
What is the genetic basis of Down Syndrome?
Trisomy 21
Mostly nondisjunction (translocation and mosaicism)
Prevalence 1 per 660
List the clinical features of Down Syndrome
- Oblique (upslanted) palpebral fissures
- Single transverse palmar crease
- Hypotonia
- Round face and flat nasal bridge
- Epicanthic folds
- Brushfield spots in iris
- Small mouth and protruding tongue
- Small ears
- Flat occiput and third fontanelle
- Short neck
- ‘Sandal gap’ between first and second toe
Describe the prognosis in Down Syndrome
IQ 20-55
Gap to normal widens through childhood
Most survive to middle age then decline due to Alzheimers
What medical conditions are associated with Down Syndrome?
- 40% have congenital heart disease, esp VSD and AVSD
- Hypothyroidism
- Alzheimer’s
- Glue ear
- Atlantoaxial instability
- Delayed motor milestones
- Short stature
- Visual impairment from cataracts, squint, myopia
- Increased risk of leukaemia and solid tumours
- Obstructive sleep apnoea
- Epilepsy
What is the genetic basis of Patau Syndrome?
Trisomy 13
List the clinical features of Patau Syndrome
- Cleft palate
- Polydactyly
- Cardiac defects
- Eye defects (microphthalmia)
- Structural defect of brain and scalp defects
Describe the prognosis in Patau Syndrome
Almost all die by age 3
What medical conditions are associated with Patau Syndrome?
- Cardiac and renal problems
What is the genetic basis of Edwards Syndrome?
Trisomy 18
More common in females
List the clinical features of Edwards Syndrome
- Small chin
- Cardiac abnormalities
- Prominent occiput
- Flexed, overlapping fingers
- Rocker-bottom’ feet
Describe the prognosis of Edwards Syndrome
Half die by 2mths
Severe LD
What medical conditions are associated with Edwards Syndrome?
- Cardiac and renal problems
What is the genetic basis of Fragile X Syndrome?
X-linked
Trinucleotide repeat expansion
Anticipation
List the clinical features of Fragile X Syndrome
- Prominent ears
- High arched palate
- Macro-orchidism
- Macrocephaly
- Characteristic facies - long face, prominent mandible, broad forehead
Describe the prognosis in Fragile X Syndrome
Speech impairment Autism in up to 50% Impulsive Shy Severe LD
What medical conditions are associated with Fragile X Syndrome?
- Mitral valve prolapse
- Epilepsy
- Scoliosis
- Joint laxity
What is the genetic basis of Prader-Willi Syndrome?
Lack of paternal 15q
List the clinical features of Prader-Willi Syndrome
- Obesity
- Hypogonadism
- Hypotonia
- Violent temper
- Sleep apnoea
- Neonatal feeding difficulties
- Faltering growth in infancy
- Learning difficulties
Describe the prognosis of Prader-Willi Syndrome
Mild LD
Expressive language disorder
What medical conditions are associated with Prader-Willi Syndrome?
- Late onset diabetes
2. Psychiatric - e.g. OCD, anxiety
What is the genetic basis of Angelman Syndrome?
Lack of maternal 15q
List the clinical features of Angelman Syndrome
- Microcephaly
2. Ataxic, jerky movements
Describe the prognosis of Angelman Syndrome
Severe LD
What medical conditions are associated with Angelman Syndrome?
- Epilepsy
2. GI conditions