discovery, incidence, genetics, signs and symptoms, tests, pregnancy, treatment.

1. HumangeneticsdepartmentPUNJABIUNIVERSITY
Presented by:- NITIN KUMAR

2. Discovery.
Incidence
Genetics and Causes.
Signs and symptoms.
Test.
Pregnancy and
Phenylketonuria
Prevention(treatment).
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3. What is phenylketonuria?
• Pku is rare condition in which baby is born
without the ability to properly break down an
amino acid known as phenylalanine.
• Phenylalanine plays an important role in
production of melanin , therefore infants
having pku has lighter skin hair and eye colour.
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4. Discovery
• In 1934 Dr. Asbjørn Følling
examined mentally retarded
children.
• Borgny Egeland and her two
children Liv and Dag.
Other name of PKU
Folling Disease,
Phenylalanine Hydroxylase
Deficiency(PAH) Disease,
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5. Incidence of PKU
• The PKU disorder is
as frequent in men
as it is in women
• 1 in 18300 in INDIA.
• 1 in 10,000 to 15,000
in United States.
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6. Genetics and causes
 Mutations in the PAH gene
cause phenylketonuria.
 Metabolic disorder.
 Autosomal recessive disorder.
 two PKU allels are required for
an individual to show symptoms
of the disorder.
 PAH gene is located on
chromosome 12 in band 12q22-
q24.1.
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8. PHENYLALANINE
HYDROXYLASE
PHENYLALANINE
Dietary
sources,
BODY
PROTEINS
BREAKDOWN
(b)
(a)
The normal metabolism of phenylalanine
(pathways a and b)
TYROSINE
Tyrosine is necessary for the production of neurotransmitters like epinephrine, norepinephrine,
and dopamine.
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9. HYDROXYPHENYLACETIC
ACID
PHENYLACETIC
ACID*
(c)
(c)
The abnormal metabolism in phenylketonuric
subjects (pathway c)
*Agents, thought to be responsible for mental retardation
PHENYLALANINE*
Dietary
sources,
BODY
PROTEINS
(b)
(a)
PHENYLALANINE
HYDROXYLASE
transaminase
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10. Signs and symptoms
 A child with PKU may look normal and
completely healthy for the first few months of
life.
 If left untreated, signs and symptoms may
appear between 3 to 6 months of age.
 Child may begin to be less active and do
things later than other children.
 Lose interest or not pay attention to things
around him.
 Musty or mousy odor of his breath, hair, skin,
or urine
 Seizures
 Skin conditions, such as eczema.
 Severe intellectual disability( Learning,
speech, or behaviour problems.)
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11. Pregnancy and Phenylketonuria
 Woman with PKU at risk for
complications if she don’t
follow a PKU meal plan
during her childbearing
years.
 This can lead to various
problems in the baby,
including:
o intellectual disabilities
o heart defects
o delayed growth
o low birth weight
o an abnormally small head
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12. Testing
• Phenylalanine level
• Blood tyrosin level
• Ferric chloride test:-
sample is dissolved in
mixture of water
and ethanol , and a few
drops of dilute ferric
chloride solution is added.
Formation of a red, blue,
green, or purple coloration
indicates the presence of
phenols ( phenolpyruvate etc ).
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13. Prevention
• Early daignosis.
• Low protein diet.
• Protein
suppliment for
life.
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