Multi-System Disorders Flashcards
(8 cards)
Describe Neurofibromatosis type 1
Autosomal dominant
Need 2+ of below to diagnose:
- cafe au lait spots >6
- neurofibromas ≥ 2
- axillary freckling
- lisch nodules (spots in iris)
- optic glioma
- thinning of long bone cortex
- FHx
Describe Myotonic dystrophy
Autosomal dominant
CTG repeat, exhibits anticipation with increases severity in each generation
Bilateral late-onset cataract
Muscle weakness, stiffness and myotonia
Low motivation, bowel probs, diabetes
Heart block
Death post-anaesthetic a risk if not monitored
Congenital
- death/severe muscle disorder and learning difficulty
Describe Tuberous Sclerosis
Autosomal dominant
Classic triad;
- epilepsy
- learning difficulties
- skin lesions
Hamartomas in different organs
How is Neurofibromatosis type 1 diagnosed and managed?
Clinical diagnosis using diagnostic criteria
Management
- annual review
- BP
- spine for scoliosis
- tibia for unusual angulation
- visual acuity and visual fields
- educational assessment
- ask patient to report unusual symptoms
Describe the genetics of neurofibromatosis type 1
Autosomal dominant
variable expression
- inter-familial and intra-familial
Gene identified - 17q
- tumour suppression gene
Mutations different in different families
- test cost around £400 so used sparingly
50% due to new mutations
- usually paternal in origin
What is the difference between NF1 and NF2
They are completely separate disorders
Main features NF2 are
- acoustic neuromas usually bilateral
- CNS and spinal tumours
- a few CAL spots
NF2 gene is on Chromosome 22
Describe the genetics of Tuberous Sclerosis
Autosomal dominant
- 60% due to new mutations
Variable expression
- severity varies between family members
Almost full penetrance
- gene carriers will have some signs even if only on scans
2 genes on differnet chromosomes both cause TS with identical phenotypes
- TSC1
- TSC2
Describe clinical features of Tuberous Sclerosis
Multi-system
Variable expression
- asymptomatic to severe mental and occasionally physical handicap
Learning difficulty 40%
- autistic features common
Seizures 65%
- infantile spasms
- myoclonic seizures
OTHER: skin lesions, kidney cysts and angiomyolipotoma, phakomas in eye, rhabdomyomas in heart
