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GROUP MEMBERS
NURUSHUHADA BT YAHYA (D20091035102)
FADILAH BT MAHMUD (D20091035094)
ROSNITAH BT YACOB (D20091035118) NUR ELIANA BT MOHMAD NOOR (D20091035093)
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STUDY CASE 1
A healthy four-year-old boy of a first degreeconsanguineous couple was noted by the parent
to have darkening of the urine to an almost
black color when it was left standing. He had anormal sibling, and there were no other medical
problems. Childhood growth and development
were normal. As a biochemist, discuss this case.
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ABOUT ALKAPTONURIA
Alkaptonuria is a rare
condition in which a
person's urine turns a dark
brownish-black color when
exposed to air especiallywhen left standing for a
period of time
A buildup of darkpigment in connective
tissues such as cartilage
and skin, is also
characteristic of thedisorder.
People of this
condition typically
develop arthritis, heart
and kidney problems.
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How it happen ????Mutation in the HGD gene.
The gene defect makes the body unable to properly
break down certain amino acids
a) Tyrosine
b) Phenylalanine
Substance called homogentisic acid builds up in the skin
and other body tissues
HA accumulates in the blood
The acid leaves the body throughurine
The urine turn brownish black when it
mix with air
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HGD GENE
The HGD gene provides instructions for making anenzyme called homogentisate oxidase
Homogentisate oxidase helps break down the amino
acids phenylalanine and tyrosine Mutations in the HGD gene impair the enzyme's role
Produce homogentisic acid(alkapton) accumulate inthe blood
Excess homogentisic acid causes damage to cartilage(ochronosis) and heart valves as well as precipitating askidney stones.