Genetics Flashcards
Mutation in Marfan syndrome
Fibrillin 1
Most common cardiac malformation in Downs syndrome
Complete atrioventricular septal defect
Mutation in Edwards syndrome
Trisomy 18
Mutation in Noonans syndrome
Defect in RAS pathway
MOA of MircoRNA
MicroRNAs (miRNAs) are small, endogenous, non-coding RNAs (length 18 to 24 nucleotides) that regulate gene expression by binding to the untranslated regions of mRNAs and inducing mRNA degradation or inhibiting protein translation. .
Gene causing MEN1 and gene causing MEN2
MEN1 = MEN1 gene MEN2 = C-RET gene
Symptoms of Wolfram (or DIDMOAD) syndrome
diabetes insipidus, diabetes mellitus, optic atrophy, and deafness
WFS1 gene
Marfan’s criteria
FBN1/ Fibrillin1 gene
Aortic root dilation
Ectopia lentis
Other features:
- Wrist-thumb sign
- pectus excarvatum
- scoliosis
Disease associated with sinus inversus
Primary ciliary dyskinesia
What is Lyonisation
X-inactivation
What is heteroplasmy
Having multiple different sets of mitochondrial DNA in one cell - affects the severity of mitochondrial diseases.
Alzheimers gene and chromosome location
APP gene. Ch 21.
Increased Alzheimers in Downs syndrome.
In females, what is the most common medical complication of Fragile X premutations?
Premature menopause
What is the primary disease mechanism for the CAG gene expansion that causes
Huntington disease?
Protein gain of toxic function
Mitochondrial disease inheritance
ALL; Mitochondrial disorders can be cause by mutations in the mitochondrial genome or in the
nuclear genome. When the mutations are in nuclear genes, they can be inherited as autosomal
dominant, autosomal recessive, or X-linked.
Gauchers disease gene, inheritance and presentation.
GD is an autosomal recessive disorder. Glucocerebroside is needed for cell membranes, it is broken down into non-toxic components in the macrophage lysosomes by the GBA enzyme. Genetic defect in the enzyme (GBA1), located on chromosome 1 causes the disease.
Presentation: Lipid filled macrophages build up in organs. Enzymes released causing scarring.
- Bone marrow - anaemia, leukopenia, thrombocytopenia
- Bone - Osteoporosis/ flask deformity
- Heaptosplenomegaly
- Neurological/ brain stem symptoms. Seizures
Mutation in DMD
deletion of multiple exons.
If large deletions or duplications are not found, then check for point mutations (less common)
Fabry’s disease gene, inheritance and presentation
Due to defect in GLA gene (alpha Gal)
GLA enzyme breaks down GL3/ ceramide/ glycosphnigolipids in lysosomes.
X-linked condition
Presentation:
- neuropathic pain
- angiokeratomas
- anhydrosis
- renal disease
- arhythmias and cardiomyopathy
- strokes
Testing - alpha gal levels for males. GLA gene for females.
Hormone profile in Turners
High FSH
High LH
low oestrogen
low progesterone
Tay Sach’s disease features
Tashya Sathyajits gang of 6 small jews.
- Tay Sachs
- Ganglioside build up
- Hexoaminidase enzyme mutation
- no hepatosplenomegaly
- occurs in Ashkenazi jews
Tay Sach’s disease features
Tashya Sathyajits gang of 6 cherry jewels.
- Tay Sachs
- Ganglioside build up
- Hexoaminidase enzyme mutation
- no hepatosplenomegaly
- cherry red spot
- occurs in Ashkenazi jews
Neiman- Pick features
Pick you big nose with your sphinger
- Neimann pick
- big liver and spleen
- sphingomyelin build up
Disease caused by WNK4
hyperkalemic hypertension/ Gordons syndrome/ Type 4 RTA/ pseudo hypoaldosteronism
FSGS gene
NPHS
