---
title: "What MCADD is and how newborn screening detects it"
language: en
topics: ["Amsterdam", "daddy", "health", "heart", "lifestyle", "mcadd"]
full_article_url: https://willem.com/en/2019-01-29_born-with-mcadd/
---
# What MCADD is and how newborn screening detects it

*A rare metabolic disorder that blocks the body from burning fat.*

> MCADD is a rare genetic metabolic disorder in which the body lacks the enzyme that breaks down medium chain fatty acids, so it cannot use fat for energy. My son's case was caught by the standard newborn screening.

The body burns glucose first, then the glycogen store in the liver, and finally fat. People with MCADD lack, or have too little of, medium chain acyl-CoA dehydrogenase, the enzyme needed to oxidise medium chain fatty acids. Once the glycogen runs out the body cannot switch to fat, which leads to sleepiness, lethargy, coma and ultimately death, while unused fatty acids can accumulate and damage liver and brain.
Days after birth my son crashed with a dangerously low body temperature and no visible cause. Standard tests found nothing. The newborn screening flagged MCADD, and additional blood and urine samples confirmed it. There was no cure when he was diagnosed. Management is practical: eat often, follow a high-carbohydrate low-fat diet, take L-carnitine if prescribed, and be prepared for illness, vomiting or long workouts.