Genetics Flashcards
Which genes are associated with early onset Alzheimer’s?
PSEN-1
PSEN-2
APP
ApoE
Which genes are associated with late onset Alzheimer’s?
ApoE
Individuals with two ApoE4 alleles are 15 times more likely to develop dementia and people with one ApoE4 allele are three times more likely to develop dementia
Which genes are associated with familial frontotemporal dementia?
C9orf72
MAPT
Which genes are associated with Huntington’s disease?
IT15 (huntingtin)
Which gene is associated with CADASIL (cerebral autosomal dominant arteriography with subcortical infarcts and leukoencephalopathy)?
Notch3
What is the inheritance pattern of neurofibromatosis (types 1 and 2)?
Autosomal dominant
What is the inheritance pattern of Huntington’s disease?
Autosomal dominant
Caused by CAG repeats
What is the inheritance pattern of achondroplasia?
Autosomal dominant
What is the inheritance pattern of noonans syndrome?
Autosomal dominant
What is the inheritance pattern of phenylketonuria?
Autosomal recessive
What is the inheritance pattern of hurlers syndrome?
Autosomal recessive
What is the inheritance pattern of Tay-Sachs disease?
Autosomal recessive
What is the inheritance pattern of friedreichs ataxia?
Autosomal recessive - caused by GAA repeats
What is the inheritance pattern of Wilson’s disease?
Autosomal recessive
What is the inheritance pattern of vitamin D resistant rickets?
X-linked dominant
What is the inheritance pattern of cerebellum ataxia?
X-linked recessive
What is the inheritance pattern of Hunters syndrome?
X-linked recessive
Which is the inheritance of fragile X syndrome?
Sex-linked - caused by CGG triplet repeats
Fragile X syndrome causes mental impairment (inherited) and is a common cause of autistic like behaviour.
What is the inheritance pattern of Lesch-Nyhan syndrome?
Sex-linked
LNS is a rare disorder that causes a build up of uric acid in the body causing gout, poor muscle control and moderate retardation. Also associated with self-mutiliating behaviour such as lip and finger biting.
What is epistasis?
The interaction of genes that are not alleles - two or more loci work together to create a new phenotype.
What is pleiotropy?
Describes how a single gene causes multiple phenotypic traits.
Which receptor gene is associated with variability in weight gain when being treated with anti-psychotics?
5-HT2c
What is the chromosomal genotype of Klinefelter’s syndrome?
47XXY
Symptoms include:
Infertility (almost universal)
Low testosterone levels
Gynaecomastia
Small testes
Poorly developed secondary sexual characteristics
Can also have a mild intellectual disability however IQ may be normal
