Genetic disorders/Diseases Flashcards

1
Q

Huntington’s disease

A
  • Trinucleotide repeats is used to diagnose HD
  • HD gene is on short arm of chromosome 4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Wilson’s disease

A
  • Low serum ceruloplasmin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Acute intermittent porphyria

A

Excessive amounts of urine prphobilinogens and aminolevulinic acide in urine
- Presents as abdominal pain, tachycardia, tingling in hands and feet, paranoia and hallucinaitons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Lambert-eaton myasthenic syndrome

A

paraneoplastic abnormality of PREsynaptic acetylcholine release, often described in conjunction with small-cell lung carcinoma
- likely immune mediated against voltage gated calcium channels on the presynaptic side of the nueromuscular junction
- generalized weakness with initial improvement after minimal exercise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Guillain Barre syndrome

A

acute inflammatory demyelinating polyneuropathy (AIDP) is a rapidly occurring demyelinating disease that can present with ascending pain, paralysis
- loss of deep tendon reflexes in the extremities
- tests of choice EMG and nerve conduction studies which reveal loss of H reflex and decreased nerve conduction velocities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Polymyositis

A

Inflammatory disease of the muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Tuberous sclerosis

A
  • Autosomal dominant
  • Nuerocutaneous disorder with a prevalence of about 1 in 6000-9000 individuals
  • seizures, mental retardation
  • cutaneous lesions include: ash leaf spot (hypomelanotic macule), adenoma sebaceum (facial angiofibromas), shagreen spots (irregularly shaped often raided or textures skin lesions on the back or flank), retinal haratomas
  • neuropathologic lesions inlcude: subependymal nodules and cortical hamartomas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Rett’s disorder

A

Pervasive developmental disorder only seen in girls, involves deceleration of head growth from ages 5 months to 4 years, loss of purposeful hand skills and development of stereotyped hand movements between 5 months and 2.5 years, loss of social engagement and acquired impairment in expressive and receptive language skills, seizures observed in up to 75% of patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

NF 1

A
  • Cafe-au-lait spots, subcutaneous neurofibromas, axillary freckling, lisch nodules (pigmented iris hamartomas), optic nerve gliomas, neurofibroms, and schwannomas.
  • caused by a mutation of NF1 gene on chromosome 17
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

NF2

A
  • Chromosome 22
  • bilateral vestibular (nerve 8) schwannomas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Williams

A

-AD
-mental retardation
- hemizygous deletion that includes the elastin locus on chromosome 7q11-q23.
- short stature, depressed nasal bridge, broad forehead, widely spaced teeth, elphin like facies
- thyroid, renal and cardiovasacualr abnormalities
- anxiety, hyperactivity, hypermusicality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What chromosomes are associated with Alzheimers

A

long arm of 21 (gene for amyloid precursor protein) and 19 (apo E4 gene)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Turners syndrome

A

female but with no secondary sex characteristics and an absence or minimal development of gonads
- one x chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

klinefelters syndrome

A

presence of an extra chromosome, xxy
-male habitus but do not develop strong male characteristics
-small, underdeveloped genitals, infertile and can develop breast tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is myasthenia gravis?

A

Autoimmune neurologic disorder involving the production of autoantibodies against postsynaptic nicotinic acetylcholinergic receptor sites on muscle
- offending antibodies cross placenta to fetus
- clinical features: diplopia, dysarthria, bulbar palsy, fatigue and muscle weakness
- deep tendon reflexes are preserved
- relationship between MG and thymoma- 10% of pts with MG have thymoma
- Edrphonium chloride is a short acting cholinergic agent used to diagnose the disorder clinically, other diagnostic tests include EMG and nerve conduction studies (decreased amplitude on repetitive stimulation), titer of serum antibodies
- Pyrostigmine is used to treat the disorder on an ongoing basis, can also use steriods, plasmapharesis, IVIG, immunosupressive agents such as azathioprine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Duchenne’s muscular dystrophy

A

-X linked recessive
- due to lack of muscle dystrophin (a protein found in muscle membrane)
- muscle weakness greater proximally
- Diminished DTR, elevated CPK, mental retardation (1/3 of cases), enlarged muscles due to fat infiltration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

SIADH vs. psychogenic polydipsia vs. diabetes insipidus

A

SIADH: Urine output decreases, more concentrated, sodium goes down
Psychogenic polydipsia: Urine output increases, less concentrated, sodium goes down
Diabetes insipidus: urine output goes up, urine is less concentrated, sodium increases

18
Q

What are short palpebral fissures seen in?

A

Fetal alcohol syndrome

19
Q

Fragile X syndrome

A
  • mental retardation
  • long ears
  • marrow face
  • short stature
  • hyperextendable joints
  • arched palate
  • macro-orchidism
  • seizures
  • autistic features
  • coincides with high rate of ADHD and learning disorders
  • second most common cause of mental retardation
  • It is the result of mutation of the X chromosome
    X linked dominant *
20
Q

What age would you expect child to tolerate mother’s absence without distress?

A

25 months

21
Q

Wilson’s disease

A

Autosomal recessive
abnormal copper metabolism-problem with incorporation of copper into ceruloplasmin and with diminished biliary excretion of copper
- excessive copper in brain-basal ganglia
- decreased cerulopasmin
clinical: parkinsonism, flapping tremor, ataxia, dystonia, bulbar signs-dysphagia and dysarthria, signs of liver failure usually present
Linked to chromosome 13
Treatment: pencillamine-copper chelating agent- can reverse deficits of disease in many cases

22
Q

Metachromatic leukodystrophy

A
  • Autosomal recessive
  • Metabolic disorder of myelin that results in deficiency of arylsulfatase A (ASA) leading to abnormal accumulation of sulfatides in the brain and peripheral nerves leading to progressive demyelination
  • gene is located on chromosome 22q13
    Clinical presentation infantile/juvenile: gait disorder w/ hypotonia and lower limb areflexia often proceed CNS involvement
    Adult onset: tends to present with progressive dementia and behavioral problems
    Both have delayed nerve conduction velocities
23
Q

Tay-sachs disease

A

-autosomal recessive
- severe infantile form of the autosomal recessive gangliosidosis
- hexosaminidase A deficiency
- retardation, paralysis, dementia, blindness and death in year 2-3
- cherry red spot on fundoscope
- hyperreactive startle response

24
Q

Lesch-nyhan syndrome

A

X linked recessive hereditary disorder of purine and pyrimidine metabolism. hyperuricemia results from a deficiency in hypoxanthine-guanine phsphoribosyltransferase
- choreoathetosis, hyperreflexia, hypertonia, dyarthria, behavioral distrurbances, cognitive impairment and self-mutilation

25
Q

Gaucher’s disease

A
  • autosomal recessive resulting from B-glucosidase deficiency
    Type 1: hematologic anomalies, hypersplenism, bone lesions, skin pigmentation, ocular pingueculae
26
Q

sturge-weber

A

neurocutaneous disorder that is sporadic and not genetically inherited
- facial cutaneous angioma usually with a brain angioma ipsilateral to the skin lesion.
- contralateral hemiparesis, mental retardation, homonymous hemianopia, seizures. Glucoma is common and if untreated can lead to blindness

27
Q

Von hippel lindau syndrome

A

-autosomal dominat
-retinal and CNS hemangioblastomas (cerbellum mostly) and visceral cysts and tumors (renal cysts), can have pheochromocytomas

28
Q

Ataxia Telangiectasia

A

Autosomal recessive
-ataxia in childhood then telangeictases (earlobes, nose, sclerae), higher risk for lymphoma and leukemia, abnormal eye movements

29
Q

Fabry’s disease

A

X-linked lysosomal storage disease
-deficiency in alpha galactosidase A
- asymptomatic red or purple papules around the umbilicus hips thighs and scrotum
corneal deposits
painful dysesthesias of distal extremities, cerebral thrombosis or hemorrhage and vascular narrowing
renal failure common cause of death

30
Q

Friedrich’s ataxia

A

autosomal recessive on chromosome 9, expansion of GAA
- gait ataxia, loss of lower extremity proprioception and absence of DTR
- dysarthria, babinski sign, eye movement abnoramlites
- death of often due to hypertrophic cardiomyopathy in 40s

31
Q

Myotonic dystrophy

A

autosomal dominant trinucleotide repeat ctg on 19
ptosis, bifacial weakness, frontal baldness, triangular drooping faces, motor weakness greater distally
- myotonia- unable to let go hand shake
- fibrotic or inflitrative cardiomyopathy
- PCR is diagnostic
EMG: myopahtic features and myotonic discharges
perifascicular muscle atrophy on histo

32
Q

trimsomy 18

A

50% dont live past first week of life
- low set ears, small jaw, hypoplastic fignernails, MR, cryptorchidism, congenital heart defect, microcephaly, renal abnormalities

33
Q

cri-du-chat

A

deletion short arm of chromosome 5
- MR, microcephaly, cat like high pitched cry, do not live past early childhood

34
Q

Prader-willi syndrome

A

Autosomal dominant disorder
15q11-q13
- high caloric intake-diabetes cardiac failure

35
Q

trinucliotide repeat diseases

A

fragile x
myotonic dystrophy
huntingtons
x-linked spinobulbar muscular atrophy
dentatorubral-pallidoluysian atrophy
spinocerebellar atrophies
fredricks ataxia

36
Q

Klinefelter’s syndrome

A

xxy
- small dysfunctional testes
- MR
- pear shaped stature

37
Q

turner’s syndrome

A
  • absence of x chromosome in genetic female (XO)
  • short stature and lack of pubertal sexual development
  • webbed neck and heart and kidney anomalies
38
Q

prader willi syndrome

A

deletion on the paternal chromosome 15
-MR, hypogonadism, hypotonia, behavior disinhibition, rapid and excessive weight gain and facial dysmorphism

39
Q

Mitochondrial encephalopathy, myopathy, lactic acidosis, and stroke-like episodes (MELAS)

A

most common mitochondrial disorder
- stroke like episodes
- onset childhood or early adult life

40
Q

Myoclonus epilepsy with ragged-red fibers (MERRF)

A
  • childhood or early adulthood
  • myoclonic seizures in childhood, ataxia and mental retardation
41
Q

leber’s hereditary optic neuropathy (LHON)

A

isolated bilateral optic neuropathy
usually males
15-35
painless and central vision loss in one eye then the other

42
Q

Kearns–Sayre syndrome (KSS)

A

-progressive external opthalmoplegia
-onset before 20
-short stature, pigmentary retinopathy, cerebellar ataxia, heart block and elevated CSF