Name that Genotype

Question 0

del(22q11.2)

Answer 0

DiGeorge syndrome or Velo-Cardio-Facial syndrome
depends on the extent of the deletion

DiGeorge: absent or hypoplastic thymus & parathyroids (T-cell issues; infections); congenital heart disease
Velo-Cardio-Facial: cleft palate, lateral nasal buildup, cardiac septal defects

Question 1

del(15q11-q13) maternal

Answer 1

Angelman syndrome
seizures
intellectual disabilities

Question 2

del(15q11-q13) paternal

Answer 2

Prader-Willi syndrome
hypotonia, hypopigmentation
hypogenitalism, obesity

Question 3

del(5p15.2)

Answer 3

Cri du chat syndrome
microcephaly, characteristic cry, seizures
intellectual disabilities

terminal or interstitial deletion on short arm of chr 5
resulting in haploinsufficiency in 5p15.2
cat cry = del(5p15.3)

Question 4

Mutation at location 5q13

long arm of chromosome 5 at position 13

Answer 4

Spinal Muscular Atrophy
SMA1 and SMA2 located here.
Mutation in SMA1 (deletion at exon 7 or SNP)

Question 5

Copy number variations in DUF1220 (across different species) is associated with what trait? On what chromosome/location is this gene found?

Answer 5

Brain Size

1q21

Question 6

47, XXY

Answer 6

Klinefelter syndrome
tall stature, hypogonadism, gynecomastia, language impairment
Sterility (common)

Question 7

45, X

Answer 7

Turner Syndrome
Short stature, webbed neck, edema of hands & feet, broad shield-like chest, narrow hips, renal & cardiovascular abnormalities, gonadal dysgenesis (Sterility; failure of ovarian maintenance)

Question 8

t(15;17)(q22;q21)

Answer 8

Acute Promyelocytic Leukemia
PML-RARalpha fusion

PML = promyelocytic leukemia = tumor supressor gene; zinc-finger family
RARalpha = retinoic acid receptor alpha
forms heterodimer with RXR and represses trxn

Question 9

t(9;22)(q34;q11)

Answer 9

ABL-BCR fusion

CML
treat with tyrosine kinase inhibitor gleevec
Philadelphia

Question 10

46 XX, t(8;21)(q22;q22)[20]

Answer 10

Acute Myelogenous Leukemia
AML-M1/M2

children with this leukemia are treated with chemotherapy ; no differentiation therapy available.

Question 11

idic15q

Answer 11

inverted, duplicated, isodicentric 15q

Autism, hypotonic, seizures (not dysmorphic)
intellectual disabilities are more severe

Question 12

15q interstitial duplication

Answer 12

If maternally duplicated: Autism, seizures, severe intellectual disability, mild hypotonia

If paternally duplicated: phenotype is normal

Question 13

15q deletion in PWSAS region on the maternal allele

Answer 13

Angleman’s syndrome

mildly dysmorphic, hypotonia in infancy, spasticity in older pts
intellectual disabilities, seizures autism, microcephaly

Question 14

del(17p11.2)

Answer 14

Charcot-Marie-Tooth disease

PMP22 peripheral myelin protein
muscle wasting
hammer toe

Question 15

del(17p11.2)

Answer 15

Charcot-Marie-Tooth disease

PMP22 peripheral myelin protein
muscle wasting
hammer toe

Question 16

loss of PMP22 gene (or mutations of it)

del(17p12)

Answer 16

Heriditary Neuropathy with liability to pressure palsies
Autosomal Dominant
age of onset usually mid 20s
limbs “fall asleep”
numbness, tingling, pasly - minutes to days to months in length per episode - in response to pressure on the nerves
PMP22 gene - peripheral myelin protein 22