SBK 3013 PRINCIPLE IN

BIOCHEMISTRYGROUP MEMBERS:GROUP MEMBERS:

AZIREN SANTHARAN (D20091035141)AZIREN SANTHARAN (D20091035141)

TUAN ZAKIAH TUAN MAHMOOD TUAN ZAKIAH TUAN MAHMOOD (D20091035112)(D20091035112)

NOR FAZILAH ZAINUL (D20091035128)NOR FAZILAH ZAINUL (D20091035128)

NURUL IZZATI MUSA (D20091035121)NURUL IZZATI MUSA (D20091035121)

CASE 3A Sickeningly sweet baby boy

Emma and J acob were so excited at the birth of their baby

Mat thew. But in the back of their minds, they really worried

because their first child, Samuel, died at the age of 9 days.

By the fifth day after birth, Mat thew began to have t rouble

nursing and by the seventh day he had completely stopped

feeding. Emma and J acob were so frant ic because it

seemed to them that Mat thew might also died. Emma and

J acob rushed him to the Emergency Room. The examinat ion

showed no infect ion and his X-rays were normal. Emma

informed the doctor that Mat thew’s diapers has funny smells.

Mat thew’s urine did have sweet, maple syrup smell and

lab results revealed elevated levels of 22

Discuss the case.

• Without treatment, brain damage can occur.

• This can cause mental retardation or spasticity.

• Some babies become blind.• If not treated, most babies die

within a few months.

Is it Dangerous???

Further InvestigationBabies are tested through

newborn screening for MSUD before they leave the hospital. The

baby’s heel is pricked and a few drops of blood are taken. The

blood is sent to the state laboratory to find out if it has

more than a normal amount of BCAAs.

more than a normal amount of BCAAs have been detected!!!! =(

Oh NO!!!!!!

WHAT IS BCAAs??Leucine, isoleucine, and valine are called

“branched-chain amino acids” (BCAAs)

because of their “tree-like” structure. They are found in all foods that contain

protein

What are the disease?? MSUD

MSUD stands for “maple syrup urine disease”. It is

named for the sweet maple syrup smell of the urine in

untreated babies. This condition is one type of

amino acid disorder. People with MSUD have problems

breaking down certain amino acids found in

protein.

What are the causes of MSUD?

• In order for the body to use protein from the food we eat, it is broken down into smaller parts called amino acids. Special enzymes then make changes to the amino acids so the body can use them.

• Classic MSUD, the most common form, is caused by the absence of a group of enzymes called “branched-chain ketoacid dehydrogenase” (BCKAD).

• The job of this enzyme group is to break down three different amino acids called leucine, isoleucine and valine. When they cannot be broken down, these amino acids build up in the blood and cause problems.

People with MSUD have a mutation in the chromosome 19 that encode for the production

of enzyme BCKD complex.

These enzymes break down the BCAAs.

When there is an alteration in these genes, enzyme levels go down and BCAAs build up in the blood stream.

How is MSUD Inherited?

• MSUD is inherited in an autosomal recessive manner. It affects both boys and girls equally.

• When both parents are carriers, there is a 25% chance in each pregnancy for the child to have MSUD. There is a 50% chance for the child to be a carrier, just like the parents. And, there is

a 25% chance for the child to have two working genes. • These chances are the same in each pregnancy with the same

parents

• Amino acid disorders (AAs) are a group of rare inherited conditions. They are caused by enzymes that do not work properly.

• Protein is made up of smaller building blocks called amino acids. A number of different enzymes are needed to process these amino acids for use by the body. Because of missing or non-working enzymes, people with amino acid disorders cannot process certain amino acids. These amino acids, along with other toxic substances, then build up in the body and cause problems.