Genetic Disorders

Question 1

Ehler danlos syndrome mutation?

Answer 1

In gene resposible for collagen sytnthesis

Question 2

Major characters of ehler danlos:

Answer 2

Hyperextensible skin
Hyperflexible and hypermobile joints

Question 3

Major complication of ehler danlos:

Answer 3

Blidness : retinal dechament or rupture globe
Death from rupture aorta
Bladder rupture and skeletal deformities

Question 4

Familial hypercholestrolemia
Mutation in:

Answer 4

Gene encoding for receptor protein (LDL receptor)

Question 5

In familial HCH mutation is impairment of:

Answer 5

LDL transport and catabolism
Leading to++ in LDL amd cholestrol in plasma》atheromas and xanthomas

Question 6

In familial cholestrolemia
Heterozygous and homozugous:

Answer 6

In hetero 2-3 fold (350mg/dl) stays asymptomatic until adult 》IHD.
In homo 5 fold (600-1200mg/dl) die in 20y from MI.

Question 7

Neurofibromatosis mutation:

Answer 7

In gene coding for protein regulating cell growth

Question 8

N.F type 1 other name:

Answer 8

Von recklinghausen disease

Question 9

N.F type 1 mutation in chromosome :

Answer 9

17

Question 10

N.F type 1 characters:

Answer 10

Multiple disfiguring n.fibromas (skin carnial n and git).
Dark pigmentation in skin (cafe au lair spots)
Pigmented iris nodule (lisch nodule)
++risk of myeloid leukaemia (200-500 times)

Question 11

N.f type 2 mutation chromosome:

Answer 11

22

Question 12

N.f type 2 characters:

Answer 12

Peripheral n.fibroma
Bilateral tumour of the 8 cranial nerve acoustic neuromas) leading to hearing loss

Question 13

Phenyle ketonuria:

Answer 13

Lack of phenylalanine hydroxylase enzyme L to accumulation of phenylalanine (hyperphenylalaninemia)

Question 14

C. Features:

Answer 14

Bad odour of urine
Mental retardation 》1/3 unable to walk &1/2 cannot talk
– skin hair pigmentation
Seizures, neurological abnormalities

Question 15

Phenyl ketonuria treated by:

Answer 15

Restriction of phenylalanine early in life

Question 16

Tay-sachs D

Answer 16

Lysosomal storage disease
Def in hexosaminidase A (gangliosides)
C.P : mental retadation, neurological dysfunction , death in 2-3 yrs

Question 17

Nieman-pick d:

Answer 17

LSD, def in sphingomyelinease (sphingomyelin)
C.p : massive visceral enlargement》 V&D, CNS symptoms, death in 1st 3-5 yrs

Question 18

Gaucher disease:

Answer 18

LSD (the monst common)
Def in glucocerbrosidase (glucosylceramide)

Question 19

Gaucher d tpyes:

Answer 19

T1 :99% hepatosplenomegally, pancytopenia or thrombocytopenia, absence of CNS involvement, long life
T2: highlt lethal, affect children 3-6 monthes of age witj CNS involvement
T3: intermediate b/w t1 &, t2

Question 20

Down syndrome

Answer 20

Trisomy 21

Question 21

Craniofacial feature of Down s

Answer 21

Flat face and occiput
Oblique palpebral fissure, epicanthal fold
Low set ears, protruded tongue

Question 22

Mental status fo Down s

Answer 22

Mental retardation, their IQs decline progressively with age

Question 23

Cvs in down s

Answer 23

CHD (ASD, VSD)

Question 24

Other trisomy variants:

Answer 24

Trisomy 13 patau syndrome
Trisome 18 edward s

Question 25

Turner’s S

Answer 25

Monosomy 45X0

Question 26

C. Features of turners s:

Answer 26

Female hypogonadism, failure of breast development
Short stature
Webbed neck, low posterior hair line
Lymphoedema
Co-artation of aorta
Primary amenorrhoea, atrophic streaky ovaries
Broad chest with widely spaced nipples

Question 27

Klinefilter syndorme

Answer 27

47 XXY
Male with more tham x chromosome

Question 28

The extra X chromosome origine
In klinefelter s

Answer 28

Could be either maternal or paternal

Question 29

Half of klinefelter s patient are lost due to:

Answer 29

Spontaneous abortion

Question 30

C. Features of klinefelter s:

Answer 30

Tall stature with + in length b/w the sole and pubic bone
Atrophiic testis》 hypogonadism
Gynacomastia
Failure of male secondary cgaracters
Minimal or no intellectual impairment
++ risk of type 2 diabetes, breast cancer and autoimmune disease.

Question 31

Most important method for diagnosis of genetic disorders:

Answer 31

Amniocentesis amd chorionic villi biopsy

Question 32

Indication of genetic disorders

Answer 32

Maternal age 35y old and over
Previous chromosomal abnormalities
History of familial inborn error of metabolsim
Family hiatory of X-linked disorders.