Genetics Flashcards
What is Wilson’s Disease? What are the complications? What is the gene mutation?
Build up/deposition of copper throughout the body
- psychiatric disorders
- hepatomegaly
- kayser-fleischer ring
- cardiomyopathy
- movement disorders (myoclonus)
- renal tubular dysfunction
- arthritis
- CNS disorders
Mutation in the ATP7B gene (autossomal recessive)
What mutation is associated with Wilson’s disease? What can be used other than this to diagnose?
Mutation in the ATP7B gene (autosomal recessive).
Low ceruloplasmin level.
Is serum copper low or high in Wilson’s Disease? Why?
Low due to deposition within the organs.
How is Wilson’s Disease managed? What are the side effects of this medication?
Penicillamine- chelates copper to reduce build up.
Can cause nephrotic syndrome, drug induced SLE, and myasthenia-gravis.
What is the karyotype for Turner’s syndrome?
45XO
What cardiac defects are associated with Turner’s syndrome?
Bicuspid aortic valve and coarctation of the aorta
What are the features of Down’s Syndrome?
congenital heart and neural defects along with changes to the physical appearance, such as a flat occiput, upslanting palpebral fissures and small, low-set ears.
What is a +ve test in the 15 week screening for Down’s?
Low AFP, low uE3, high bHCG
What causes myotonic dystrophy type 1?
Trinucleotide repeat disorder of DMPK gene - autosomal dominant
What are the clinical features of myotonic dystrophy type 1?
- Face: frontal balding, bilateral ptosis, long and thin face, cataracts
- Speech: dysarthria
- Neck: SCLM wasting
- Hands: percussion myotonia, distal wasting, slow reflex grip
- Internal features: testicular trophy, metabolic syndromes and insulin resistance, arrhythmias, cardiomyopathies
What causes Friedrich’s Ataxia? What is the usual age of onset?
Trinucleotide repeat disorder.
10-15 y/o.
What are the clinical signs of Friedrich’s ataxia?
- Neurological signs: ataxia, dysarthria, lower limb weakness, upgoing plantares, sensory impairments
- External signs: muscle wasting, kyphoscoliosis, high arched palate
- Internal: HOCM (systolic murmur), reduced visual acuity, T1DM, deafness
Edward’s Syndrome is a trisomy of which chromosome? What are the clinical features?
Trisomy 18, heart defects (VSD), oesophageal atresia, omphalocele, microcephaly, low set ears, overlapping digits.
Patau’s Syndrome is a trisomy of which chromosome? What are the clinical features?
Trisomy 13,cleft palate, microcephaly, intelectual disability, polydactyly.
What is Noonan’s Syndrome caused by? What are the clinical features?
Mutation in PTPN11, SOS1, and RIT1 gene mutations are all attributable,
Most common is PTPN11 (50%).
Pulmonary stenosis, short stature and a webbed neck.
What mutation causes Marfan’s Syndrome?
What is the inheritance pattern?
Fibrillin-1 mutation on chromosome 15q21.
Autosomal dominant.
What chromosome is affected in Prader-Willi Syndrome?
Loss of function of genes of the paternal copy of chromosome 15.
What are the signs of Marfan’s Syndrome?
- Tall and thing with unusually long limbs
- Arachnodactyly
- High-arched palate
- Cardiovascular cx
- Ophthalmic cx
- MSK abnormalities
- Neurological abnormalities
What are the signs/symptoms of Prader-Willi Syndrome?
- Poor feeding in infancy
- Hyperphagia in later childhood
- Morbid obesity
- Hypotonia
- Short stature
- Developmental delay
- Skin picking which results in cellulitis
What causes fragile X syndrome?
CGG trinucleotide repeat on FMR1 gene on X chromosome.
What are the manifestations of fragile X syndrome?
- Intellectual disability
- Anxiety
- Autistic features
- Long face
- Protruding ears
- Hypermobile joints
- post-pubertal macroorchidism (large testes).
