Random Flashcards
What is the frequency of congenital heart malformations?
4 to 8 per 1000 births
What is the frequency of cleft lip with or without cleft palate?
1.4 per 1000 newborns worldwide
What percentage of individuals with cleft lip with or without cleft palate are male?
60 to 80%
What is the most common flow lesion in Congenital Heart Disease?
VSD 0.17% pop incidence
PDA 0.083%
ASD 0.066%
Aortic stenosis 0.044%
What is the reccurence risk of schizo in a child of an affected parent?
9-16%
What percentage of individuals with 22q11.2 del will develop schizo?
25%
What percentage of Hirschsprung disease is isolated? Chromosomal syndrome?
70% and 12%
What is the Hardy-Weinberg law?
The law that relates allele frequency to genotype frequency, used in population genetics to determine allele frequency and heterozygote frequency when the incidence of a disorder is known
What is stratification?
The situation in which a population contains a number of subgroups whose members have not freely and randomly mated with members of other subgroups
What is assortative mating?
Selection of a mate with preference for a particular genotype; nonrandom mating. Usually positive.
What is Fitness?
The probability of transmitting one’s genes to the next generation (1 is the same as gen pop; 0 means does not reproduce)
What is a founder affect?
A high frequency of a mutant allele in a population founded by a small ancestral group when one or more of the founders was a carrier of the mutant allele.
What is genetic admixture?
The merging into the gene pool of an immigrant population with allele frequencies different from the already existing population, which, if there is random mating, results in new allele frequencies reflecting the mixing of the two populations
At how many weeks of a pregnancy is an Rh-negative pregnant person given Rh immune globulin?
At 28 to 32 weeks of gestation and after pregnancy.
What occurs when a pregnant person is Rh-negative and has a fetus that is Rh-positive?
Rh-positive blood cells from the fetus enter the pregnant person’s blood stream, thus causing the production of anti-Rh antibodies that return to the fetal circulation and damage the fetal red blood cells, causing hemolytic disease of the newborn
What is heterozygote advantage?
Environmental conditions that favor the reproductive fitness of carriers of deleterious mutations
Which disorders of imprinting have higher rates in ART?
Risk for BWS after IVF is ~1 in 4000
Angelman syndrome
PWS is not increased in ART
What are the three most common BRCA mutation in the AJ population?
BRCA1 185delAG and 5382insC
BRCA2 6174delT
What percentage of a newborn’s hemoglobin is HbF (alpha2gamma2)?
70%
What is the variant that causes Sickle Cell Anemia?
Glu6Val in the beta-globin gene.
What is the recurrence risk of CHARGE syndrome when the mutation is de novo?
5%
What does CHARGE syndrome stand for?
Coloboma
Heart defects
Atresia of the choanae
Retardation of growth and development
Genital abnormalities
Ear anomalies
What is the rate of germline mosaicism in DMD?
5-15%
What genotype/ phenotype is a good prediction of exocrine pancreatic function?
Delta508 homozygotes typically have pancreatic insufficiency
Arg117His tend to be associated with pancreatic sufficiency
What is projection?
Projection is a type of counter tramsference in which a counselor has made assumptions about the experience of a patient
What is protective identification?
When a situation is extremely challenging to the counselee and she is not able to bring forward adequate psychological defences to respond.
What is the frequency of Turner syndrome?
1/2,000-2,500 live births
What percentage of 45,X results in spontaneous loss?
99%
What percentage of Turner syndrome have a karyotype of monosomy?
45-50%
What percentage of Turner syndrome have structural alterations and what percentage are isochromosome?
20%
15-18 isochrom (most frequent)
What percent of Turner syndrome have differing amounts of Y chromosome? What is the concern?
6-12%
Gonadal malignancy
What is the frequency of Klinefelter syndrome?
1/600 male births
What percentage of Klinefelter syndrome are mosaic for 46X,Y?
15-20%
What is the cause of 47XYY?
Two sperm fertilizing an egg
What is the frequency of 47XYY?
1 in 1000
What is the reproductive risk of 47,XXX?
Less than 50% but not well-defined
You have a cf DNA result showing normal female. The ultrasound shows male genitalia. What are your differential diagnoses?
Sample mix-up or lab error
Androgen exposure - CAH, maternal ovarian tumor, exogenous androgens, aromatase deficiency
Translocation of SRY to X Chr
Mosaicism -45,X/46,XY or 46,XX/46,XY
SOX9 duplication
What is the most common Robertsonian translocation?
13/14
What is the most common reciprocal translocation? What is the risk for gametes?
11/22
3:1 segregation causing an extra chromosome with material from 11 and 22
What disorder results from UPD on chromosome 6?
Transient Neonatal Diabetes
Two Paternal Chr
6q24
What disorder results from UPD on chromosome 14?
Temple syndrome
Two Paternal Chr
14q32
What is the phenotype of Temple syndrome?
IUGR, polyhydramnios, developmental delay, thoracic and abdominal defects
What percentage of males have a chromosomal abnormality associated with their infertility?
~8%
2% were reciprocal translocations
What percentage of male and female premutation carriers will develop FXTAS?
30-40% of males over 50 years (fhx)
8-16% females
What is the median expected survival for an individual born with CF after 2015?
45 - 50 year old
What percentage of men with CF will have CBAVD?
98%
The common F508del mutation in CFTR is primarily classified as what class variant?
Class II (missense and aa del); CFTR trafficking and processing defect
All of these disorders are caused by repeats in non-coding regions of DNA except:
a. Huntington disease
b. Friedreich’s Ataxia
c. C9Orf72-related disorders
d. ALS
a. Huntington disease
A patient presents to clinic with high CK levels, seizures, cobblestone lissencephaly and hydropcephalus. She is 6
months old and has had symptoms since birth. The family reports no signficant family history. What single gene would
you most want to order testing for?
a. POMT1
b. FKTN
c. COL6A2
d. CNBP
a. POMT1
Facio-scapulo-humeral muscular dystrophy is unique from many other muscular dystrophies because it is
a. progressive
b. childhood onset
c. due to repeat contraction
d. due to repeat expansion
c. due to repeat contraction
Which symptom of CF has an inverse relationship with the amount of CFTR function in an individual?
a. sweat chloride levels
b. pancreatic function
c. lung function
d. all of the above
a. sweat chloride levels
Which of the following is worth the most points on the systemic score defined by the Ghent criteria?
a. skin striae
b. myopia
c. hindfoot deformity
d. scoliosis
c. hindfoot deformity
Which disease is incorrectly matched with the DNA repair process that it causes defects in?
a. Xerodema pigmentosa; base excision repair
b. Cockayne syndrome; nucleotide excision repair
c. MUTYH-related polyposis; base excision repair
d. Lynch syndrome; mismatch repair
a. Xerodema pigmentosa; base excision repair
Should be nucleotide excision repair
Which of the following genes does not play a role in homologous recombination repair?
a. BRCA1
b. BRCA2
c. BRIP1
d. ATM
d. ATM ( phosphorylating key substrates involved in DNA repair)
What ethnicity is most likely to be a 2:0 carrier for SMA?
african american
What is the chance that a mother of a son with Fragile X has trinucleotide repeats in the normal range on both alleles?
0%
She has to be at least a premutation carrier.
In Fragile X, what is the chance that a premutation can expand to a full mutation?
The chance the premutation could expand to a full mutation ranges from 95-100%.
The recurrence risk is higher if the index case is female in what condition?
A. neural tube defect
B. Profound childhood deafness (etiology unknown)
C. Cleft palate
D. Pyloric stenosis
E Lethal osteogenesis imperfecta
A. neural tube defect
Birth defects that occur more frequently in males that females include all except:
A. Anencephaly
B. Pyloric stenosis
C. Hirschprung disease
D. Clubfoot
E. Cleft lip with our without cleft palate
A. anencephaly
0.6 F to 0.4 M
What is the inbreeding coefficient for 1st degree relatives?
1/4
What is the inbreeding coefficient for 2nd degree relatives (aunt-nephew, half sibs)?
1/8
What is the inbreeding coefficient for 3rd degree relatives (first cousins)?
1/16
What is the inbreeding coefficient for first cousins once removed?
1/32
What is the inbreeding coefficient for second cousins?
1/64
Which of the following disorders is associated with renal cysts?
TSC1
TSC2
NF1
NF2
Basal cell nevus syndrome
TSC2 when there’s a contiguous deletion of TSC2 and PKD1
