# DGAT‐1 deficiency: Congenital diarrhea and dietary treatment

## TL;DR

DGAT-1 deficiency causes severe diarrhea in infants, but a specific diet with C8 MCT oil and supplements can lead to full recovery.

## Contribution

A successful treatment plan using C8 MCT oil instead of C8/C10 mixtures for DGAT-1 deficiency is presented.

## Key findings

- A very-low-fat diet with C8 MCT oil led to full remission and normalized weight in a DGAT-1 deficient infant.
- C8 MCT oil did not cause diarrhea, unlike other fat sources.
- Omega-3/6 supplementation is necessary to prevent essential fatty acid deficiency.

## Abstract

DGAT‐1 (Diacylglycerol Acyltransferase‐1) deficiency is an autosomal recessive disorder which causes severe impairment in lipid absorption. We report a case of an infant suffering from persistent diarrhea starting at the age of four weeks. Further investigations identified DGAT‐1 deficiency as underlying cause. A treatment plan was developed which included a very‐low fat diet administered as infant formula, essential fatty acid supplementation, C8 medium chain triglycerides‐ and fat‐soluble vitamin supplementations. The patient was put into full remission after administration of the treatment plan and weight curves normalized at the 50th percentile at the age of 24 months. Intermittent episodes of loose stools were due to an excessive intake of fructose via extensive fruit consumption. DGAT‐1 deficiency is a rare genetic disease which leads to congenital diarrhea and is especially dangerous in infancy. Our treatment plan put the patient into full remission showing that C8 MCT oil should be preferred over treatment with C8/C10 mixtures.

DGAT‐1 deficiency causes severe impairment in lipid absorption.This leads to persistent diarrhea, which is especially dangerous in infancy.Cases reported in the literature used solely fat‐restricted/‐free diets to treat patients.

DGAT‐1 deficiency causes severe impairment in lipid absorption.

This leads to persistent diarrhea, which is especially dangerous in infancy.

Cases reported in the literature used solely fat‐restricted/‐free diets to treat patients.

We were able to put the patient into full remission by administering a very low‐fat diet, including caprylic acid (C8) medium‐chain triglyceride (MCT) oil, which led to the normalization of weight percentiles.C8 MCT oil did not cause diarrhea in our patient.To prevent essential fatty acid deficiency, an omega‐3/6 supplement should be advised.

We were able to put the patient into full remission by administering a very low‐fat diet, including caprylic acid (C8) medium‐chain triglyceride (MCT) oil, which led to the normalization of weight percentiles.

C8 MCT oil did not cause diarrhea in our patient.

To prevent essential fatty acid deficiency, an omega‐3/6 supplement should be advised.