The Genome

CMECNE

Sickle Cell Disease: Screening and Key Points

Learning Objectives and CME/Disclosure Information

This activity is intended for healthcare providers delivering care to women and their families.

After completing this activity, the participant should be better able to:

1. Discuss carrier screening for sickle cell disease
2. Explain symptoms of sickle cell disease

Estimated time to complete activity: 0.5 hours

Faculty:

Susan J. Gross, MD, FRCSC, FACOG, FACMG President and CEO, The ObG Project

Disclosure of Conflicts of Interest

Postgraduate Institute for Medicine (PIM) requires faculty, planners, and others in control of educational content to disclose all their financial relationships with ineligible companies. All identified conflicts of interest (COI) are thoroughly vetted and mitigated according to PIM policy. PIM is committed to providing its learners with high quality accredited continuing education activities and related materials that promote improvements or quality in healthcare and not a specific proprietary business interest of an ineligible company.

The PIM planners and others have nothing to disclose. The OBG Project planners and others have nothing to disclose.

Faculty: Susan J. Gross, MD, receives consulting fees from Cradle Genomics, and has financial interest in The ObG Project, Inc.

Planners and Managers: The PIM planners and managers, Trace Hutchison, PharmD, Samantha Mattiucci, PharmD, CHCP, Judi Smelker-Mitchek, MBA, MSN, RN, and Jan Schultz, MSN, RN, CHCP have nothing to disclose.

Method of Participation and Request for Credit

Fees for participating and receiving CME credit for this activity are as posted on The ObG Project website. During the period from 08.10.23 through 08.10.25, participants must read the learning objectives and faculty disclosures and study the educational activity.

If you wish to receive acknowledgment for completing this activity, please complete the test and evaluation. Upon registering and successfully completing the test with a score of 100% and the activity evaluation, your certificate will be made available immediately.

Joint Accreditation Statement

In support of improving patient care, this activity has been planned and implemented by the Postgraduate Institute for Medicine and The ObG Project. Postgraduate Institute for Medicine is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team.

Physician Continuing Medical Education

Postgraduate Institute for Medicine designates this enduring material for a maximum of 0.5 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Continuing Nursing Education

The maximum number of hours awarded for this Continuing Nursing Education activity is 0.5 contact hours.

Designated for 0.25 contact hours of pharmacotherapy credit for Advance Practice Registered Nurses.

Read Disclaimer & Fine Print

SUMMARY:

Sickle cell disease is a common genetic condition that affects the function of adult hemoglobin. It has a high prevalence in people with African, Middle Eastern, and West Indian ancestry. Any pregnant woman who reports a high-risk ethnicity should be screened with hemoglobin electrophoresis, which is highly accurate in detecting carriers of sickle cell trait. Many reproductive carrier screening genetic panels also include screening for sickle cell carrier status. (For more on screening, see ‘Related ObG Topics’ below).

Background and Genetics

Sickle cell disease is caused by a single point mutation within the HBB gene
RBCs have a “sickled” shape and decreased ability to carry oxygen
Autosomal recessive
Hemoglobin electrophoresis is recommended for diagnosis and carrier screening
- Confirmed by the presence of Hemoglobin S (HbS)
- Other hemoglobin variants (HbC, HbE, beta thalassemia) can cause disease when inherited with a sickle cell mutation

Symptoms

Sickle Cell Disease / Sickle Cell Anemia

Abnormally shaped RBCs aggregate and block small blood vessels (microvascular occlusions)
Intermittent episodes of acute pain (sickle cell crisis)
Organ damage and risk of stroke
Swelling of hands and feet
Chronic hemolysis
High risk of infection (septicemia, meningitis)

Sickle Cell Trait / Sickle Cell Carrier

Generally asymptomatic
Normal CBC
Hb electrophoresis shows 40-50% HbS
May experience vaso-occlusive events with extreme dehydration, physical exertion, or high altitude

Management

Prophylactic antibiotics to manage risk of infection
Symptom-based therapies for pain and other complications
Hydroxyurea may be used to increase the amount of functional HbF in the blood
Severe cases may require RBC transfusions or bone marrow transplantation
Recent trials using the latest gene therapy techniques show promise to treat sickle cell disease (see ‘Learn More – Primary Sources’ below for more detail)
- Gene addition: Adding a therapeutic beta-globin gene)
- Gene editing: Correction of the mutated β-globin gene

KEY POINTS:

Prevalence
- Approximately 10% of Black Americans are carriers of sickle cell disease
- Highest incidence in West Africa: 1 in 4 individuals are carriers
In addition to symptom-based therapy, treatment may include RBC transfusions or bone marrow transplantation
- Recent trials with gene addition and gene editing techniques are an important area of research
Prenatal diagnosis via CVS or amniocentesis is available for at-risk pregnancies
- Molecular testing is required for fetal diagnosis
- There are no fetal ultrasound findings typically associated with this diagnosis
Pregnant patients with sickle cell disease may experience complications such as thrombosis, infections, preterm birth, preeclampsia, and cardiac failure
- Refer to Maternal Fetal Medicine and Hematology
- Review vaccinations, including pneumococcal, meningococcal and Haemophilus influenzae

Learn More – Primary Sources:

ACOG Committee Opinion 691: Carrier Screening for Genetic Conditions

GeneReviews: Sickle Cell Disease

Hematopoietic Stem Cell Gene-Addition/Editing Therapy in Sickle Cell Disease

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