Symptoms, Warning Signs, and Emergency Care

Because Hereditary Folate Malabsorption (HFM) affects both the body’s ability to create blood cells and the central nervous system’s ability to function, symptoms can appear in several different ways. No two children have the exact same experience; some may first show signs of severe anemia, while others may experience seizures or a loss of developmental milestones ^[1][2].

Common Symptoms in Infancy

Symptoms typically begin between 2 and 4 months of age as the folate stores a baby is born with begin to run out ^[3].

• Blood and Energy Changes: The most common sign is megaloblastic anemia, where the body produces red blood cells that are too large and do not work correctly ^[1]. You may notice your child looks very pale, seems unusually tired, or is easily winded. In some cases, all types of blood cells—red cells, white cells, and platelets—can become low, a condition called pancytopenia ^[2][4].
• Growth and Digestion: Many children experience failure to thrive, meaning they do not gain weight or grow at the expected rate ^[1]. Chronic diarrhea and painful oral ulcers (mouth sores) are also frequently reported and can make feeding difficult ^[4][5]. These mouth ulcers can have infectious or hematologic causes and warrant assessment by a clinician.
• Immune System Issues: HFM often causes hypogammaglobulinemia, which is a low level of protective antibodies in the blood ^[1]. This makes children very susceptible to recurrent infections, particularly pneumonia and other respiratory illnesses ^[6][4].

Neurological Symptoms

Because the central nervous system is deficient in folate, neurological signs are common. These may appear at the same time as blood issues or may develop later if the brain deficiency is not corrected ^[3].

• Developmental Delay or Regression: A child may be slow to reach milestones like sitting up or rolling over. Most concerning is regression, where a child suddenly loses a skill they already had ^[1][7].
• Seizures: Seizures have been reported in a subset of affected children ^[1]. These seizures can sometimes be difficult to control until central nervous system folate levels are properly supported ^[8].

When to Seek Care: General Guidelines

Because symptoms vary so widely, you must follow the written emergency plan provided by your child’s hematology or metabolic team. Below are general guidelines on what typical warning signs look like.

Tier 1: Emergency (Call Local Emergency Services / 911)

These symptoms indicate a life-threatening crisis, such as sudden organ distress or severe blood loss.

• Severe Bleeding: Coughing up blood, heavy uncontrolled bleeding, or sudden signs of internal bleeding ^[9].
• Breathing Distress: Blue-tinted skin/lips, severe gasping for air, or signs of severe respiratory distress ^[9].
• Uncontrolled Seizures: A first-time seizure, a seizure that lasts longer than your doctor’s prescribed threshold (often 5 minutes), or multiple seizures where the child does not wake up in between ^[1].
• Loss of Consciousness: If your child becomes floppy, unresponsive, or impossible to wake up.

Tier 2: Urgent (See a Doctor Today or Go to the ER)

These symptoms suggest a serious complication that needs evaluation within hours.

• Fever Guidelines: A rectal temperature of 38.0°C (100.4°F) or higher in an infant younger than 3 months is always an urgent medical issue. Additionally, if your child has a known low white blood cell count (neutropenia), any fever is a medical emergency requiring immediate evaluation and antibiotics, as they cannot fight infections normally ^[4]. Follow your specific neutropenia action plan.
• Bruising and Petechiae: Unusual bruising or small, flat, pinpoint red or purple dots on the skin (petechiae). This can be a sign of dangerously low platelets ^[2][9].
• Acute Regression: A sudden, noticeable loss of a developmental skill or a rapid change in alertness.
• Severe Dehydration: No wet diapers for several hours, no tears when crying, or a sunken soft spot.

Tier 3: Contact Your Care Team (Call the Doctor’s Office)

Call your child’s metabolic specialist or pediatrician if you notice these worsening trends:

• Feeding Refusal: If your child is consistently refusing to eat or shows signs of mild dehydration.
• Worsening Mouth Sores: New or increasingly painful ulcers that interfere with comfort or feeding ^[4].
• Increased Fatigue: If your child seems more listless or pale than usual.
• Persistent Diarrhea: Worsening digestive issues that do not resolve with standard care ^[2].