Symptoms and Warning Signs of Enteropeptidase Deficiency
At a Glance
In babies, enteropeptidase deficiency commonly causes persistent diarrhea or vomiting, poor feeding, and poor weight gain. Swelling, marked sleepiness, breathing trouble, green vomit, bleeding, or dehydration require urgent medical evaluation.
In the first few months of life, a baby with congenital enteropeptidase deficiency may appear to be healthy at first. However, symptoms typically emerge as the lack of protein digestion begins to take a toll on their body [1][2]. Understanding your child’s symptoms and knowing when to seek urgent care is a critical part of managing this condition.
Primary Symptoms in Infancy
The earliest signs usually involve the digestive system and growth. Because the body cannot “turn on” the enzymes needed to break down protein, food passes through the system partially undigested [3].
- Chronic Diarrhea and Vomiting: Many infants experience frequent, loose, or even “intractable” diarrhea that does not resolve with standard formula changes [2][1].
- Poor Weight Gain: This is often the most distressing symptom for parents. Despite regular feedings, your child may not gain weight or may even lose weight because they cannot absorb the nutrients required for growth [3][1].
- Feeding Issues: Some babies may seem constantly hungry because they aren’t absorbing nutrients, while others may become too fatigued to eat effectively [1].
Secondary Symptoms: The Impact of Malnutrition
When the body cannot digest protein, it leads to broad malnutrition and hypoproteinemia (low blood protein). This can trigger several “secondary” symptoms [3][1]. It is important to note that these symptoms require clinical evaluation, as they can have multiple causes.
- Generalized Edema (Swelling): Protein in the blood (specifically albumin) acts like a sponge, keeping fluid inside your blood vessels. When protein levels drop too low, fluid leaks out into the surrounding tissues [1]. You may notice puffiness in the face, hands, feet, or a swollen-looking belly.
- Severe Pallor and Anemia: Your child may look unusually pale (pallor). This is often due to anemia, a condition where the body doesn’t have enough healthy red blood cells [3]. This can be caused by low protein, but also iron, folate, or B12 deficiencies [1].
- Skin Lesions: Some infants develop a peeling, scaly, or red rash, often around the mouth, diaper area, or limbs [4][1]. These look like acrodermatitis enteropathica, a condition caused by primary zinc deficiency. Your doctor will need to evaluate the rash to determine if it is due to general malnutrition, zinc deficiency, or another cause [4][1].
When to Seek Emergency Care
Do not normalize persistent diarrhea, vomiting, or poor feeding. If your child’s baseline symptoms worsen, you should contact your care team promptly. Severe malnutrition and protein deficiency can lead to acute medical crises requiring hospital stabilization [1].
Seek immediate emergency care if you observe any of the following:
| Symptom | What it may indicate |
|---|---|
| Severe Lethargy or Inability to Wake | If your child is “floppy,” unresponsive, or unusually weak, they may be experiencing a severe metabolic crisis, infection, or dehydration [1]. |
| Breathing Difficulty | Fast, labored breathing, grunting, or a blue/gray tint to the lips or skin requires immediate help. |
| Abnormal Bleeding or Bruising | Malnutrition can lead to coagulopathy (poor blood clotting), often due to Vitamin K deficiency or liver strain [1]. Watch for uncontrolled bleeding, bloody stools, or bleeding gums. |
| Bilious (Green) or Severe Vomiting | An inability to keep any feeds down, or vomiting green fluid, is a medical emergency. |
| Rapidly Worsening Swelling | If swelling (edema) becomes severe or spreads quickly, it can interfere with organ function [1]. |
| Severe Dehydration | Markedly reduced urine output, no tears when crying, or a sunken “soft spot” on the head. |
If you are ever in doubt about your child’s hydration or breathing, go to the nearest emergency room. Before your child is fully stabilized on treatment, they may need hospital-based IV fluids, nutritional support, or electrolyte correction.
Common questions in this guide
What are the first signs of congenital enteropeptidase deficiency in a baby?
What causes swelling in a baby with enteropeptidase deficiency?
Which warning signs mean my baby needs emergency care?
Could a rash be related to congenital enteropeptidase deficiency?
When do diarrhea or vomiting become more serious?
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References
References (4)
- 1
Enterokinase deficiency associated with novel TMPRSS15 gene mutations: a case report.
Li Y, Li R, Pan Y, et al.
Frontiers in pediatrics 2025; (13()):1484208 doi:10.3389/fped.2025.1484208.
PMID: 39944319 - 2
Novel Compound Heterozygous TMPRSS15 Gene Variants Cause Enterokinase Deficiency.
Wang L, Zhang D, Fan C, et al.
Frontiers in genetics 2020; (11()):538778 doi:10.3389/fgene.2020.538778.
PMID: 33061943 - 3
Activation of Human Pancreatic Proteolytic Enzymes: The Role of Enteropeptidase and Trypsin.
Freiburghaus AU, Roduner J, Hadorn HB
JPGN reports 2021; (2(4)):e138 doi:10.1097/PG9.0000000000000138.
PMID: 37206452 - 4
Enterokinase deficiency with novel TMPRSS15 gene mutation masquerading as acrodermatitis enteropathica.
Chen Y, Li Z, Liu C, Wang S
Pediatric dermatology 2023; (40(2)):389-391 doi:10.1111/pde.15197.
PMID: 36410965
This page is for informational purposes only and does not constitute medical advice. It explains symptoms and warning signs of congenital enteropeptidase deficiency, but your child's care team or emergency services should guide decisions about urgent care.