Metabolic Disorder In Infants/Babies - Causes & Symptoms You Should Be Aware Of

Image : Shutterstock

Is your baby undergoing various health checks soon after birth? Do you find these tests alarming? Well, if you are clueless about the relevance of these screening tests for newborns, reading this post may be of help!

Infant screening tests are effective methods to diagnose health issues that may need medical treatment. Have you heard about metabolic disorder in infants? Abnormal chemical reactions in the body may disrupt the metabolic process. Want to know how it may affect your darling baby? Read on!

What Is Metabolism And Metabolic Disorder?

Metabolism means the process by which your body creates energy from the food you eat. Your body breaks up the food you eat into various sugars and acids, which in turn act as fuel for your body. This fuel can be used up by your body right away. It can also be stored by your body in its various organs like the body fat, muscles or liver. A metabolic disorder takes place when there are various chemical changes in your body that affect this process. In such a condition, your body may have too much of a particular substance, or too little of the ones that are needed to stay healthy (1).

What Causes Metabolic Disorder In An Infant?

A metabolic disorder is an inherited disorder. It is a rare gene mutation. In the case where both parents have any record of a metabolic disorder, the infant has a higher chance of the same (2).

What Are The Symptoms Of Infant Metabolic Disorder?

Most of the conditions related to infant metabolic disorder are rare but it is extremely crucial for all babies to be screened for the same. In some cases, babies appear to be perfectly healthy after birth and even until a few years, before any symptom shows up. These symptoms can appear at any age later in life, even after the baby has reached adulthood.

Here are some of the most common metabolic disorders that may appear in infants. Keep a look out for the symptoms as mentioned:

1. Phenylketonuria (PKU):

In this condition, an infant’s body is not able to metabolize the amino acid known as phenylalanine. This amino acid is most commonly found in breast milk, cow’s milk and meat. When it cannot be metabolized, it starts getting accumulated in the blood stream. This can affect brain development and cause severe mental retardation (3).


  • Seizures
  • Delay in mental as well as social skills
  • Rashes on the skin, like eczema
  • Small size of the head as compared to a regular body head ratio
  • Bad smelling breath or urine
  • Body odor
  • Hyperactivity

2. Galactosemia:

In this condition, an infant’s body is not able to convert the galactose, which is a type of milk sugar, into glucose, which is the sugar that is found in the blood. When the galactose is not able to turn into glucose, it starts to build up inside the body. This can cause a lot of health and medical complications and damage the baby’s liver, kidneys, brain and eyes. It can also lead to severe vomiting, liver diseases, kidney failure, mental retardation, and in some cases, even death (4)


  • Aversion to milk
  • A poor appetite
  • Jaundice
  • Poor or no weight gain
  • Convulsions
  • Vomiting

3. Medium-Chain Acyl-CoAdehydrogenase (MCAD) Deficiency:

In this condition, an infant’s body is not able to convert the fat into energy. In this case, there are no symptoms present at the time of birth. Symptoms start to appear somewhere between the second month till the second year of an infant’s life. This condition can lead to damage of the brain and liver. In severe cases, it can also be fatal. Symptoms mostly show up when the baby is off his or her feed for a long time (5).


  • Low blood sugar or hypoglycemia
  • Weakness and lethargy
  • Vomiting

4. Maple Syrup Urine Disease (MSUD):

In this condition, the baby will not have an enzyme that helps to metabolize the three essential amino acids that are needed for growth. This can lead to a buildup of the amino acids in the blood stream. It can cause poor feeding habits in the baby and cause a distinct maple syrup like smell in the baby’s urine (which is why the condition is named so). In severe cases, it can cause mental retardation and can also lead to coma and death (6).


  • Difficulties in feeding
  • Weakness and lethargy
  • Seizures
  • Vomiting
  • Maple syrup like smell in the urine
  • Coma

The problem with metabolic disorders is that the symptoms are often confused with other conditions. In most cases, symptoms end up being ignored. Keep a look out for any of the symptoms mentioned above. Speak to your baby’s doctor regularly.

Do you know of any infant who was diagnosed with an infant metabolic disorder? When were the symptoms noticed? Do share the experience here with other moms, to spread awareness among those who may be ignorant of such an ailment.

Was this information helpful?