Will I Pass Hereditary Spherocytosis to My Child?

If you have hereditary spherocytosis (HS), the chances of passing it on to your child depend on the specific genetic form of the condition you have. For most people (about 75% of cases), HS is inherited in an autosomal dominant pattern, meaning there is a 50% chance of passing the condition to each child ^[1][2]. However, there are other inheritance patterns, and genetic testing can help clarify your personal risk.

Hereditary spherocytosis is caused by changes (mutations) in the genes that provide instructions for building red blood cell membranes ^[3][4]. When these membranes are weakened, the red blood cells become sphere-shaped and are prematurely trapped and destroyed by the spleen ^[3][4].

Autosomal Dominant Inheritance (Most Common)

In roughly 75% of hereditary spherocytosis cases, the condition is autosomal dominant ^[1]. This means you only need one copy of the mutated gene to have the disease.

• If you have this form, you have a 50% (1 in 2) chance of passing the gene—and the condition—to each of your children ^[1][2].
• This form is most often linked to mutations in the ANK1, SPTB, or SLC4A1 genes ^[5][6].

Autosomal Recessive Inheritance (Less Common)

Less frequently, HS follows an autosomal recessive pattern, often involving the SPTA1 or EPB42 genes ^[7][8]. In recessive inheritance, a person must inherit two copies of the mutated gene (one from each parent) to develop the condition.

• If you have autosomal recessive HS, it means you have two copies of the mutated gene. You will definitely pass one copy to your child, making them a carrier ^[7].
• A “carrier” child who inherits only one mutated recessive gene will generally live a completely normal, healthy life without symptoms ^[9].
• Your child will only develop the disease if your partner also passes down a mutated gene. If your partner is not a carrier, your child’s risk of having the disease is effectively zero ^[9].

Spontaneous (De Novo) Mutations

Sometimes, a person is born with HS even though neither parent has the condition or carries the gene. This is called a de novo (new or spontaneous) mutation, and it most commonly occurs in the ANK1 gene ^[10][11]. If you are the first and only person in your family to have HS, you likely have a de novo mutation. If you have a de novo mutation, your chances of passing it to your children will follow the autosomal dominant pattern (a 50% chance) ^[11].

Family Planning and Genetic Counseling

Even within the same family, the severity of hereditary spherocytosis can vary widely from person to person ^[12][9]. Symptoms in a child could range from very mild (requiring no treatment) to more severe (requiring frequent blood transfusions or surgical removal of the spleen).

If you are the one carrying the child, you should also discuss the physical demands of pregnancy with your doctor. Pregnancy can place extra stress on your body, potentially worsening your anemia or increasing your risk of gallstones ^[12].

Because the genetics can be complex, working with a genetic counselor can be highly beneficial when planning a family ^[13]. A genetic counselor can help you:

• Identify your specific mutation: Genetic testing can confirm which gene is involved and determine whether your HS is dominant or recessive ^[1][14]. (Note: While genetic testing is highly accurate, there is a small chance it may not identify the specific causative mutation in every single patient).
• Screen your partner: If you have the recessive form, your partner can be tested to see if they are a carrier.
• Explore reproductive options: For families wishing to prevent the transmission of a known HS mutation, advanced options like preimplantation genetic testing (PGT) are available ^[15]. PGT is used during in vitro fertilization (IVF) to test embryos for the genetic mutation before they are implanted in the uterus.