Genetics & The Maternal Connection (AFLP/HELLP)

For many families, the journey with LCHAD deficiency begins long before the newborn screening results arrive. It often starts with a life-threatening pregnancy complication. Understanding the genetic link between a baby’s LCHAD deficiency and a mother’s health can be deeply validating for mothers who felt their bodies “failed” during pregnancy ^[1][2].

The Genetics of LCHAD

LCHAD deficiency is an autosomal recessive condition. This means that for a child to be born with the condition, they must inherit one non-working copy of the HADHA gene from each parent ^[3].

• The Parents (Carriers): Both the mother and father are usually “carriers.” They have one working gene and one non-working gene. Carriers typically do not have any symptoms of LCHAD deficiency in their daily lives ^[3].
• The 1 in 4 Rule: For every pregnancy between two carriers, there is a 25% (1 in 4) chance the baby will have LCHAD deficiency, a 50% chance the baby will be a carrier like their parents, and a 25% chance the baby will not have the mutation at all ^[3].
• The Common Mutation: The most frequent genetic change found in LCHAD deficiency is called the G1528C mutation (also written as c.1528G>C) ^[4].

The Maternal Connection: AFLP and HELLP

A unique and critical feature of LCHAD deficiency is its effect on the mother during pregnancy. About one-third of all cases of Acute Fatty Liver of Pregnancy (AFLP) are linked to the baby having an LCHAD or MTP deficiency ^[1]. Many mothers also experience HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets) ^[5].

Why This Happens

This isn’t just a coincidence; it is a biological interaction between the mother and the fetus:

1. Toxic Overflow: An LCHAD-deficient fetus cannot break down long-chain fats. These partially broken-down fats (3-hydroxy fatty acids) are toxic ^[6].
2. Shunting to the Mother: The fetus shunts these toxic fats through the placenta and into the mother’s bloodstream, expecting her liver to process them ^[6][5].
3. The Mother’s Limit: Because the mother is a carrier, she already has 50% less LCHAD enzyme activity than a non-carrier. Her liver becomes overwhelmed by the toxic fats from the baby, leading to liver inflammation, high blood pressure, and potential organ failure ^[6].

Validating the Mother’s Experience

If you experienced AFLP or HELLP, it is important to know that it was not your fault. Your body was trying to process metabolic waste that it wasn’t equipped to handle due to a rare genetic match ^[2].

Post-Partum and Future Care

• Recovery: For most mothers, liver and kidney function return to normal shortly after the baby is delivered ^[7]. However, you should ensure your doctor has confirmed that your liver enzymes and blood pressure have fully stabilized.
• Future Pregnancies: If you choose to have more children, the risk of AFLP recurring is estimated to be around 20% (1 in 5) if the next baby also has LCHAD deficiency ^[8]. It is essential to work with a Maternal-Fetal Medicine (MFM) specialist who understands LCHAD deficiency to monitor you and the baby closely from the very beginning ^[9][10].

Understanding this connection turns a traumatic medical event into a biological explanation, allowing you to focus on your recovery and your child’s long-term health ^[2].