Disease

Question 1

Prader Willi Syndrome Symptoms

Answer 1

• excessive eating
• short stature
• hypogonadism
• some degree of intellectual disability

Question 2

Prader Willi Syndrome Cause

Answer 2

del(15q11-q13) on paternal chromosome. ( PWS region is methylated on maternal 15)

Question 3

Angelman Syndrome Symptoms

Answer 3

• short stature
• severe intellectual disability
• spasticity
• seizures

Question 4

Angelman Syndrome Cause

Answer 4

del(15q11-q13) on maternal chromosome. (AS UBE3A region is methylated on the paternal 15)

Question 5

Spinal Muscular Atrophy

Answer 5

Mutation in an unstable region 5q13

Question 6

DiGeorge Syndrome

Answer 6

del(22q11.2)
absent or hypoplastic thymus and
parathyroids, congenital heart
disease

Question 7

Macrocephaly and autism

Answer 7

caused by duplications on 1q21

Question 8

Microcephaly and schizophrenia

Answer 8

caused by deletions on 1q21

Question 9

Trisomy 18 symptoms

Answer 9

Small for gestational age, microcephaly, clenched hands with overlapping fingers, rocker bottom feet

Question 10

Turner syndrome

Answer 10

45, X most common chromosome abnormality in SABs, 99% of fetuses do not make it to full term. 1/2500 female live births, short stature, webbed neck, coarctation of aorta, normal intelligence, infertility

Question 11

What are the Turner Syndrome karyotypes?

Answer 11

45, X
46, X, i(Xq) (paracentric inversion)
mos 45, X/46, XX
mos 45, X/46, X, i(Xq)

Question 12

Klinefelter Syndrome

Answer 12

47, XXY. 1/1000 liveborn males.
Sx: tall, hypogonadism, underdeveloped secondary sexual characteristics, learning disabilities, hypospadias, gynecomastia, infertility.
50% comes from maternal meiotic error, 75% of which is meiosis 1- maternal age effects

Question 13

rec(8)

Answer 13

Derived from an inv(8)(p23.1q22.1) Leads to trisomy 8q22.1 and monosomy 8p23.1
Sx: Developmental delay, congenital heart disease, thin upper lip
Founder effect- San Luis Valley 2-300 years ago

Question 14

Aniridia

Answer 14

inv(11)(p13p15) paracentric inversion

Question 15

Miller-Dieker syndrome

Answer 15

del(17p13.3)
lissencephaly (agyria)
profound intellectual disabilities

Question 16

Smith-Magenis syndrome

Answer 16

del(17p11.2)

Question 17

Potocki-Lupski Syndrome

Answer 17

dup(17p11.2)

Question 18

Hereditary Neuropathy with Liability to Pressure Palsies (HNPP)

Answer 18

del(17p12)

Question 19

Charcot-Marie-Tooth Neuropathy, type 1A

Answer 19

dup(17p12)

Question 20

17q21.31 recurrent microdeletion syndrome

Answer 20

del(17q21.31)

Question 21

Alagille syndrome

Answer 21

del(20p12)

Question 22

Cat-Eye Syndrome

Answer 22

dup(22q11)

Question 23

X-Linked Ichthyosis

Answer 23

del(Xp22.3)

Question 24

Cystic Fibrosis (allelic heterogeneity)

Answer 24

Caused by a mutation of the CFTR gene. If the mutation is deltaF508 it causes more severe pancreatic symptoms than R117H mutation, but has smaller effect on lungs. This means that other factors account for variability in lung sx.

Question 25

Alzheimer’s Disease

Answer 25

Presinilin genes on chromosomes 1 and 14.
APP gene on chromosome 21
APOE gene on chromosome 19

Question 26

IDIC 15 (Maternal)

Answer 26

Caused by isodicentric inversion duplication. Leads to autism, seizures, hypotonia. Non-dymorphic.

Question 27

Interstitial duplication on maternally derived chromosome 15

Answer 27

Leads to autism, seizures, hypotonia. Non-dymorphic.

Question 28

Jacob’s Syndrome

Answer 28

47 XYY.
Sx: Tall, learning disabilities, autism, behavioral/emotional issues.
1/1000 male births

Question 29

Triple X Syndrome

Answer 29

47 XXX
Sx: Tall, learning disabilities, seizures, kidney abnormalities
1/1000 newborn girls

Question 30

Androgen Insensitivity Syndrome

Answer 30

46XY. X-linked mutation in AR gene. Can lead to undervirilization or even complete sex reversal

Question 31

5-Alpha-reductase deficiency

Answer 31

46XY. X-linked mutation in AR gene prevents testosterone from being converted to dihydrotestosterone. This leads to undervirilization with greater virilization during puberty

Question 32

Denys-Drash and Frasier syndromes

Answer 32

46 XY. Mutation in WT1 gene (a transcription factor for SRY gene) causes sex reversal. Other sx- Wilms tumor and kidney issues

Question 33

Congenital Adrenal Hyperplasia

Answer 33

46 XX with ambiguous genitalia due to 21-hydroxylase deficiency. Also causes salt wasting with decreased Na, Cl and increased K

Question 34

Achondroplasia

Answer 34

Autosomal Dominant
Mutation of FGFR3 on chromosome 4p16.3
Causes rhizomelic limb shortening and genu varum
80% new mutation with paternal age effect

Question 35

Retinoblastoma

Answer 35

Autosomal Dominant
Mutation of RB1 gene on chromosome 13
90% penetrance

Question 36

Neurofibromatosis type 1

Answer 36

Autosomal Dominant
Causes cafe au lait spots, neurofibromas
Mutation of the NF1 gene on 17q11.2
Autosomal dominant, but need to acquire a mutation on the other allele to show phenotype

Question 37

Tuberous Sclerosis

Answer 37

Autosomal Dominant
Hypopigmented patches, angiofibromas, lung, heart, kidney issues
Cause by loss of function mutation of TSC1 (9) and TSC2 (16)

Question 38

Osteogenesis Imperfecta Type 1

Answer 38

Autosomal Dominant
Causes multiple fractures, mild short stature, adult onset hearing loss, blue sclera
Mutation of COL1A1 on 7q21.3

Question 39

Marfan Syndrome

Answer 39

Autosomal Dominant
Causes aortic root enlargement, ectopia lentis
Mutation of FBN1 gene on 15q21.1

Question 40

Huntington Disease

Answer 40

Autosomal Dominant, Anticipation
More than 40 CAG repeats in exon on 4p16.3
Earlier onset if paternal in origin

Question 41

Myotonic Dystrophy

Answer 41

Autosomal Dominant, Maternal anticipation

More than 50 CTG repeats in 3’ UTR of MPK gene on 19q13.3