Question

What would happen if we cannot process an amino acid that is needed by our body? Can you describe a disease associated with defects in the amino acid biosynthetic pathway?

Answer 1

Amino acids are crucial monomers. They form various essential polypeptide and proteins. They are also crucial metabolic intermediates in synthesis of many neurotransmitters like serotonin, GABA, Dopamine etc. The inability to process amino acid can have serious consequences like accumulation of toxic substances which can cause serious health issues or even death also. These issues are generally genetic in nature so people with this kind of disorder should avoid eating certain foods which they kind process. These conditions are generally known as amino acid metabolism disorder.

Early detection of these disorders is necessary for better management of the condition. In various countries following amino acid metabolic disorders are screened at birth of new child.

Argininosuccinic acidemia (ASA)

Citrullinemia (CIT)

Homocystinuria (HCY

Maple syrup urine disease (MSUD)

Phenylketonuria (PKU)

Tyrosinemia type I (TYR I)

Arginosuccinic acidemia: In this disorder body was unable to remove arginosuccinic acid or ammonia from blood. It can lead to brain, liver and cognition related minor or major issues. It can also affect physical development.

Citrullinemia: It belongs to class of urea cycle disorders where body was unable to remove ammonia from the body. It has similar impact on body as arginosuccinic acidemia since in both disorder accumulation of ammonia in blood leads to various complications. If this condition is not treated in new born babies, the chances of survival of baby is quite less.

Homocystinuria: In this disorder, the body was unable to metabolize homocysteine. HCY can lead to serios problems related to bones, blood, eyes, heart and pancrease.

Maple syrup urine disease: In this disorder, the body was unable to break down leucine, isoleucine and valine. If left untreated, the body can have serious issues related to brain and spinal cord. It can further lead to coma and seizures.

Phenylketonuria: In this disorder, the body was unable to break down phenylalanine. It can lead cognitive problems, seizures, mental and behavioural issues.

Tyrosinemia: It is a disorder related to tyrosine amino acid. It can cause kidney and liver related problems. It can also leads to seizures, rickets, coma and death.