Genetics- Multisystem Disorder Flashcards
How can the genetics of multisystem disorders exist?
Mutations or Inherited
What chromosomal mutations can exist?
Numerical
Structural
What is an example of a numerical chromosomal mutation?
Trisomy 21
What are examples of structural chromosomal mutations?
Translocations
Deletions
Microdeletions
What are single gene disorders that can cause multisystem disorders?
Autosomal dominant
Autosomal recessive
X-linked
What is an example of an autosomal dominant single gene disorder?
Muscular dystrophy
What is an example of an autosomal recessive single gene disorder?
Cystic fibrosis
What is an example of an X-linked single gene disorder?
Duchenne muscular dystrophy
What is a common problem with multisystem disorders?
Variable expression within as well as between families- sometimes difficult to predict phenotype from genotype
What type of condition is neurofibromatosis Type 1?
Autosomal dominant
What is the NHS diagnostic criteria for Neurofibromatosis Type 1?
2 or more of: • café au lait spots - 6 or more • neurofibromas - 2 or more • axillary freckling • Lisch nodules (specks in iris) • optic glioma • thinning of long bone cortex • family history
How is Neurofibromatosis Type 1 diagnosed?
Clinical diagnosis using diagnostic criteria
What is done for someone at risk of neurofibromatosis type 1 until diagnosis can be excluded?
Annual review of affected individuals and at risk children until diagnosis can be excluded (5 years)
What is checked for in someone with possible neurofibromatosis type 1?
- BP
- spine for scoliosis
- tibia for unusual angulation
- visual acuity and visual fields
- educational assessment
What are some other possible features of Neurofibromatosis type 1?
- Learning difficulties
- Scoliosis
- Pseudoarthrosis of the tibia
- Raised BP