Loading....
Coupon Accepted Successfully!

Biochemistry

Open Flashcards

Purines, Pyrimidines and Nucleic Acid Metabolism

Question
37 out of 59
 

NARP syndrome seen in (AIIMS Nov 2009)



A Mitochondrial disease
B Glycogen storage

C Lysosomal storage
D None

Ans. A Mitochondrial disease

The mutation in mitochondrial dna has been associated with variable syndromes of differing severity

Mitochondrial DNA associated (mtDNA-associated) Leigh syndrome and NARP are part of a continuum of progressive neurodegenerative disorders observed in members of the same family caused by abnormalities of mitochondrial energy generation.

Leigh syndrome. Stringent diagnostic criteria for Leigh syndrome were

a. Progressive neurologic disease with motor and intellectual developmental delay

b. Signs and symptoms of brainstem and/or basal ganglia disease

c. Raised lactate concentration in blood and/or cerebrospinal fluid (CSF)

d. One or more of the following:

Leigh-like disease. The term "Leigh-like disease" is often used for individuals with clinical and other features that are strongly suggestive of Leigh syndrome but who do not fulfill the stringent diagnostic criteria because of atypical neuropathology (variation in the distribution or character of lesions or with the additional presence of unusual features such as extensive cortical destruction), atypical or normal neuroimaging, the lack of demonstrated lactic acidosis, or incomplete evaluation.

NARP. Diagnosis of NARP is based on the following clinical features:

a. Neurogenic muscle weakness. Electromyography (EMG) and nerve conduction studies may demonstrate peripheral neuropathy (which may be a sensory or sensorimotor axonal polyneuropathy).

b. Ataxia. Cerebral and cerebellar atrophy may be noted on MRI.

c. Retinitis pigmentosa. The ocular manifestations of NARP are extremely variable and range from a mild salt and pepper retinopathy to bull's eye maculopathy and classic retinitis pigmentosa with bone spicule formation Ophthalmologic examination may reveal pigmentary retinopathy or optic atrophy. Electroretinogram (ERG) may reveal abnormalities (including small-amplitude waveform) or may be normal. ERG may demonstrate predominantly cone dysfunction in some pedigrees and mainly rod dysfunction in others.

In addition, neuropathy, seizures, and learning difficulties are usually present.

Genes

a. Mitochondrial DNA-associated Leigh syndrome. The mitochondrial genes MT-ATP6, MT-TL1, MT-TK, MT-ND1, MT-ND3, MT-ND4, MT-ND5, MT-ND6, MT-CO3, MT-TW, and MT-TV are associated with mtDNA-associated Leigh syndrome.

b. NARP. MT-ATP6 is the only gene associated with NARP.

Purines, Pyrimidines and Nucleic Acid Metabolism Flashcard List

59 flashcards
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
27)
28)
29)
30)
31)
32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
42)
43)
44)
45)
46)
47)
48)
49)
50)
51)
52)
53)
54)
55)
56)
57)
58)
59)