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R
i lo n di truy n
FRIEDREICH’S ATAXIA
What is Friedreich’s ataxia?
This is an autosomal recessive condition that causes neural
degeneration.
Causes
•
Mutation of FXN gene on chromosome 9 causes GAA
repeats and abnormal frataxin production.
Signs and symptoms
•
Abnormal gait.
•
Speech disturbance.
•
Cardiomyopathy.
Investigations
•
Genetic testing.
•
Nerve conduction studies.
•
ECG for cardiac complications.
•
Vitamin E levels: rule out vitamin E deficiency as a
differential diagnosis.
Treatment
•
Conservative: patient and parent education. Refer to
physiotherapy and speech and language therapy.
•
Medical: there is no specific treatment for this condition.
Manage complications.
Bi n ch ng
•
B nh cơ tim
•
V o c t s ng
•
Bàn chân qu p (c chân cao)
•
Đái tháo đư ng
•
Gi m thính l c
PHENYLKETONURIA
What is phenylketonuria?
This is an autosomal recessive disease in which levels of
phenylalanine increase due to the lack of phenylalanine
hydroxylase (PAH). Phenylalanine is subsequently converted
to phenylpyruvate instead of tyrosine.
Causes
•
Mutation in the gene that codes for PAH.
Signs and symptoms
•
Asymptomatic at birth.
•
Severe learning difficulties.
•
Seizures.
Investigations
•
Guthrie heel prick test is diagnostic.
Treatment
•
Conservative: parent education. Genetic counselling.
•
Patients are on lifelong low phenylalanine diet.
Complications
•
Neurobehavioural problems.
•
Seizures.
Thi u máu h ng c u
hình li m
(Xem trang 94)
Thalassaemia
Xem trang 96.
Xơ nang
Xem trang 22.
MAP 13.6 Autosomal
Recessive Conditions
Map 13.6 Di truy n gen l n NST thư ng
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