Why You No Find Me

Front 1

What is the genetic term? Give an Example?

Neither 2 alleles are dominant

Back 1

Co-dominance, blood groups (A,B,AB)

Front 2

What is the genetic term? Give an Example?

Nature and severity of phenotype vary from 1 individual to another.

Back 2

Incomplete Penetrance

Front 3

What is the genetic term? Give an Example?

1 gene has >1 effect on an individual's phenotype.

Back 3

Pleiotropy, PKU.

Front 4

What is the genetic term? Give an Example?

Differences in phenotype depend on whether the mutation is of maternal or paternal origin.

Back 4

Imprinting, Prader-Willi/Angelman syndrome.

Front 5

What is the genetic term? Give an Example?

Severity of the illness gets worse or age of onset of disease is earlier in succeeding generations.

Back 5

Anticipation, Huntington's disease

Front 6

What is the genetic term? Give an Example?

If the pt inherits or develops mutation in a tumour suppressor gene, the completmentory allele must be deleted or mutated before the Ca develops.

Back 6

Loss of heterozygosity, Retinoblastoma

Front 7

What is the genetic term? Give an Example?

Exerts a dominant effect. A heterozygote produces a non-functional altered protein that also prevents the normal gene product from functioning.

Back 7

Dominant negative effect, Mutation of Tx factor in its allosteric site (mutated form binds DNA preventing functioning protein from binding.

Front 8

What is the genetic term? Give an Example?

Tendency for certain alleles at 2 linked loci to occur together more often than expected by chance. Measured in the population,not in the family & varies with populations.

Back 8

Linkage disequilibrium, -.

Front 9

What is the genetic term? Give an Example?

Cells in the body differ in genetic make up due to postfertilisation loss of genetic material.

Back 9

Mosaicism, lyonization (random X inactivation in females).

Can be GERMLINE MOSAIC, which may produce disease that is not carried by the parent's somatic cells.

Front 10

What is the genetic term? Give an Example?

Mutations at different loci can produce the same phenotype.

Back 10

Locus heterogeneity, Marfan's, MEN 2B, homocystinuria.
Albinism.

Front 11

What is the genetic term? Give an Example?

Presence of both normal and mutated mtDNA, resulting in variable expression in mitochondrial inherited disease.

Back 11

Heteroplasmy

Front 12

What is the genetic term? Give an Example?

Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent.

Back 12

uniparental disomy.

Front 13

What is the Hardy Weinberg equilibrium equation?

Back 13

p^2 + 2pq +q^2 = 1 and p+q=1

in X-linked recessive disease - males = q and females = q^2

Front 14

What disease? What genetic defect?

Mental retardation, hyperphagia, obesity, hypogonadism, hypotonia.

Back 14

Prader-willi syndrome.

Has normal inactivated maternal allele. Paternal allele is deleted in chromosome 15 or unipaternal disomy (both Maternal).

Front 15

What disease? What genetic defect?

Mental retardation, seizures, ataxia, inappropriate laughter ("the happy puppet")

Back 15

Angelman's Syndrome.

Has normal inactivated paternal allele. Maternal allele is deleted in chromosome 15 or unipaternal disomy (both Paternal).

Front 16

Which inheritance pattern?

Often due to defects in structural genes. Many generations, both male and female, affected.

Back 16

Autosomal dominant

Front 17

Which inheritance pattern?

25% of offspring from 2 carrier parents are
affected. Often clue to enzyme deficiencies.
Usually seen in only 1 generation.

Back 17

Autosomal Recessive

Commonly more severe than AD diseases, pt often present in chilhood.

Front 18

Which Inheritance Pattern?

Sons of heterozygous mothers have a 50%
chance of being affected. No male-to-male
transmission.

Back 18

X-linked recessive.

Commonly more severe in Males, females must be homozygous to be affected.

Front 19

Which Pattern of inheritance?

Transmitted through both parents. Either male
or female offspring of the affected mother may
be affected, while all female offspring of the
affected father are diseased.

Back 19

X-linked dominant.

Front 20

Which pattern of inheritance?

Transmitted only through mother. All offspring of affected females may show signs of disease. Often clue to failures in oxidative phosporylation.

Back 20

Mitochondrial inheritance.

Front 21

What is the mechanism of Hypophosphatemic rickets?
What patttern of inheritance is seen?

Back 21

inherited disorder resulting in increased phosphate wasting at the proximal tubule. results in rickets like presentation.

Front 22

Mitochondrial myopathies types?
What pattern of inheritance?

Back 22

Leber's hereditary optic neuropathy (acute loss of central vision), myoclonic epilepsy, mitochondrial encephalopathy.

"ragged red fibers" on microscopy.
Mitochondrial inheritance.

Front 23

Which disease & mode of inheritance?

Cell signaling defect of FGF-receptor 3. Pt presents with dwarfism; short limbs; BUT head and trunk are normal.
Associated with advanced paternal age.

Back 23

Achondroplasia

Front 24

Which disease & mode of inheritance? gene mutated?

Pt presents with flank pain, haematuria, HTN, progressive renal failure. Bilateral, massive enlargement of kidneys due to multiple cysts.

Back 24

Autosomal Dominant polycystic kidney disease (ADPKD).
Gene: PKD1 (90%), chromosome 16.

Associated with berry aneurysm, polycystic liver disease, mitral valve prolapse.

Front 25

Which disease & mode of inheritance? Gene (& chromosome)?

Colon becomes covered with adematous polyps after puberty. progresses to Colon cancer unless resected.

Back 25

Familial adematous polyposis, AD.
Gene: APC gene (chromosome 5)

Front 26

Which disease & mode of inheritance?

Elevated LDL due to defective or absent LDL receptor. Heterozygotes (1:500) have cholestrol of approx 300mg/dl. homozygotes have 700mg/dl, early severe atherosclerotic disease and tendon xanthomas. Mi may develop before age 20.

Back 26

familial hypercholestrolemia, AD.

Front 27

Which disease & inheritance pattern?

inherited disorder of the blood vessels. pt presents with telangiectasia, epistaxis, skin discolouration and Arteriovenous malformations.

Back 27

Hereditary Hemorrhagic telangiectasia (osler-weber-rendu syndrome

Front 28

Which disease & inheritance pattern?

Spheroid erythrocytes due to spectrin or ankyrin defect; hemolytic anemia; increased MCHC. Splenectomy is curative.

Back 28

Hereditary Spherocytosis

Front 29

Which disease & inheritance pattern? Chromosome?

Pt presents with depression, progressive dementia, choreiform movements, caudate atrophy, and Decreased levels of GABA and ACh in the brain. Symptoms manifest in affected individuals between the ages of 20 and 50.

Back 29

Huntington's disease, AD/

Chomosome 4, trinucleotide CAG repeats

Front 30

Which disease & inheritance pattern?

Fibrillin gene mutation causing a connective tissue disorder affecting skeleton, heart, and eyes. Findings:
tall with long extremities, pectus excavatum, hyperextensive joints, and long, tapering fingers and
toes (arachnodactyly); cystic medial necrosis of aorta resulting in aortic incompetence and dissecting aortic
aneurysms; floppy mitral valve. Subluxation of lenses.

Back 30

Marfan's Syndrome

Front 31

Which disease & inheritance pattern? What gene mutation is associated with the Type 2?

Characterized by familial tumors of endocrine glands,
including those of the pancreas, parathyroid, pituitary, thyroid, and adrenal medulla.

Back 31

Multiple endocrine neoplasias (1, 2A, 2B)
2A and 2B associated with the ret gene.

Front 32

Which disease & inheritance pattern? Chromosome?

pt with cafe-au-lait spots, neural tumors, Lisch nodules (pigmented iris hamartomas). Also marked
by skeletal disorders (e.g., scoliosis) and optic pathway gliomas.

Back 32

Neurofibromatosis type I (Von Recklinghausen's syndrome)

Chromosome 17 = no. letters in "von Recklinghausen"

Front 33

Which disease & inheritance pattern? Gene & Chromosome affected?

Bilateral acoustic schwannomas, juvenile cataracts.

Back 33

Neurofibromatosis 2.

NF2 gene on chromosome 22.

Front 34

Which disease & inheritance pattern?

Pt with facial lesions (adenoma sebaceum), hypopigmented "ash leaf spots" on skin, cortical and
retinal hamartomas, seizures, mental retardation, renal cysts and renal angiomyolipomas, cardiac
rhabdomyomas, increased incidence of astrocytomas.

Back 34

Tuberous sclerosis.

Incomplete penetrance, variable presentation.

Front 35

Which disease & inheritance pattern? Gene & Chromosomes affected?

Pt with hemangioblastomas of retina/cerebellum/medulla; about half of affected individuals develop multiple bilateral renal cell carcinomas and other tumors

Back 35

Von Hippel-Lindau Disease AD

VHL gene on chromosome 3.

Front 36

List the autosomal recessive diseases. (10)

Back 36

1. Albinism
2. ARPKD
3. Cystic Fibrosis
4. glycogen storage diseases
5. Haemochromatosis
6. mucoppolysaccaridoses (except Hunter's)
7. phenylketonuria
8. sickle cell anaemia
9. Sphingolipidoses (except Fabry's)
10. thalassemias.

Front 37

List the X-linked recessive diseases (10).

Back 37

Be Wise, Fool's GOLD Heeds Silly Hope.
Bruton's agammaglobinemia,
Wiskott-aldrich syndrome
Fabry's Disease
G6PD Deficiency
Ocular albinism
Lesch-Nyhan syndrome
Duchenne's MD
Hunter's Syndrome
Hemophilia A & B

Front 38

Which gene is affected in Cystic fibrosis?

Back 38

CFTR gene often a deletion of Phe 508.

Front 39

What would you expect in a patient with Duchenne's MD? How does it differ from Becker's?

Back 39

Weakness begins in the pelvic girdle muscles progressing superiorly. Onset in those younger than 5y.o. Characteristic - Gower's sign reuqiring upper body assistance to stand.

Becker's is less severe and presents in adolescence or early adulthood.

Front 40

What is the pathology of Duchenne's MD?

Back 40

X-linked frame shift resulting in deletion of the dystrophin gene. This results in accelerated muscle breakdown. Dystrophin helps anchor the muscle fibers, primarily in skeletal and cardiac muscle.

Front 41

What Inheritance pattern and gene is affected in Fragile X Syndrome?

Back 41

X-linked Trinucleotide repeat disorder (CGG) in the FMR1 gene.

Front 42

Which Disease?

Macro orchidism, Long face with long jaw, large everted ears, autism, mitral valve prolapse.

Back 42

Fragile X syndrome.

2nd most common cause of mental retardation.

Front 43

Which Disease?

Trinucleotide repeat - CGG

Back 43

Fragile X syndrome

Front 44

Which Disease?

Trinucleotide repeat - CAG

Back 44

Huntington's Disease

Front 45

Which Disease?

Trinucleotide repeat - CTG

Back 45

Myotonic dystrophy

Front 46

Which Disease?

Trinucleotide repeat - GAA

Back 46

Friedreich's Ataxia

Front 47

What are the Findings in a pt with Down Syndrome?
What is the Genetic defect in Down Syndrome?

Back 47

mental retardation, flat facies, prominent, epicanthal folds, simian crease, Gap between 1st 2 toes, duodenal atresia, Congenital heart disease.

Trisomy 21. 95% due to meitotic nondisjunction

Front 48

What is associated with down's syndrome?

Back 48

ALL, Alzheimer's disease.

Front 49

What is the risk of having a Down syndrome baby at <20y.o.? At >45y.o.?

Back 49

1:1500 ni a mother <20y.o
1:25 in a mother >45y.o

Front 50

What will an antenatal screen show in a mother with a Down syndrome Baby?

Back 50

low a-fetoprotein, estriol.
High inhibin A, high B-HCG

ultrasound shows increased nuchal translucency

Front 51

Which Disease & gene affected?

Severe mental retardation, rocker-bottom feet, micrognathia, low-set ears, clenched hands, prominent occiput, congenital Heart disease.

Back 51

Edwards syndrome, Chromosome 18 trisomy (1:8000)

Front 52

What will antenatal test show in edward's syndrome

Back 52

low aFP, B-hCG, estriol
normal inhibin A

Front 53

Which Disease & chromosome affected?

severe mental retardation, rocker bottom feet, micropthalmia, microencephaly, cleft lip/palate, holoprosencephaly, polydactyly, congenital heart disease. Death usually < 1 y.o.

Back 53

Patau's Syndrome, Trisomy 13 (1:15000)

Front 54

Which Disease and chromosomal alteration?

Pt with microencephaly, moderate to severe mental retardation, high-pitched crying, epicanthal folds, cardiac abnormalities (VSD).

Back 54

Cri Du chat Syndrome, microdeletion of the short arm of chromosome 5.

Front 55

Which disease & chromosomal alteration?

elfin facies, mental retardation, hypercalcemia, well-developed verbal skills, extreme friendliness w strangers, cardiovascular problems.

Back 55

Williams syndrome, microdeletion of the long arm of chromosome 7.

Front 56

What are the 22q11 deletion syndromes?

Back 56

Variable presentation - Cleft palate, Abnormal facies, Thymic aplasia, Cardiac defects, Hypocalcemia - 2ndry to Parathyroid aplasia.

Digeorge - thymic, parathyroid, cardiac defects.
Velocardiofacial - palate, facial, cardiac defects.