S,S Disease (Sickle Cell Anemia), Hemoglobin Disorder Screening -Infant

S,S Disease (Sickle Cell Anemia), Hemoglobin Disorder Screening -Infant

S,S Disease (Sickle Cell Anemia), Hemoglobin Disorder Screening

Summary of Recommendation and Evidence

Population

Recommendation

Grade
(What's This?)

Screening of both Genders

The genetic screening for S,S Disease (Sickle Cell Anemia) is recommended.

B

Sickle cell disease is a rare inherited blood disorder. It is characterized by the presence of sickle or crescent shaped red blood cells (erythrocytes) in the bloodstream. 

OVERVIEW

A red blood cell disorder caused by the presence of hemoglobin S in the absence of hemoglobin A. When deoxygenated, hemoglobin S causes red blood cells to deform into a sickle shape and become brittle. These cells are rapidly removed from the circulation, resulting in anemia, and cause occlusion of small blood vessels, resulting in injury to organs, ischemic pain, and increased risk of infection. Variant forms exist.

SCREENING

Finding

Presence of Hemoglobin F, S, C without Hemoglobin A

Tested By

Isoelectric focusing (IEF) (in Utah)

PREVALENCE

About 1:500 African-American births and 1:1,000-1,400 Hispanic-American births. It occurs in African, Mediterranean (Greek, Turkish, Italian), Arabian, Indian, and Hispanic populations more commonly than in Northern European populations.

INHERITANCE

Hb S/C is inherited in an autosomal recessive manner. It affects both boys and girls equally.

PRENATAL TESTING

Genetic diagnosis by amniocentesis, CVS, or fetal blood sampling.

CLINICAL CHARACTERISTICS

Symptoms and symptom severity vary by individual. Onset may occur in infancy or childhood, but usually after 4 months of life.

Symptoms may include:

  • Anemia
  • Jaundice
  • Pain (most likely due to ischemia from vaso-oclussion)
  • Enlarged spleen, followed by autosplenectomy
  • Fever
  • Increased susceptibility to infection, particularly with pneumococcus
  • Acute chest syndrome (associated with infection, surgery/general anesthesia, pulmonary infarction or embolism)
  • Leg ulcers
  • Fatigue
  • Pneumonia
  • Splenic sequestration
  • Bone damage
  • Kidney damage
  • Aplastic crisis (associated with parvoviral infection)
  • Gallstones
  • Priapism
  • Bloody urine
  • Stroke

 

If not treated appropriately, patients may experience:

  • Spleen damage and infections
  • Eye damage and blindness
  • Growth retardation
  • Delayed maturation

EARLY SIGNS

Signs of sickle cell anemia (Hb SS) usually begin a couple of months after birth. In some cases, signs may not appear until childhood. 

Early signs of Hb SS include:

  • Sleeping longer or more often
  • Tiredness
  • Difficulty breathing
  • Pain or swelling in the hands or feet
  • Cold hands or feet
  • Pale skin

These signs can occur if your baby has a low number of red blood cells or if the sickle-shaped red blood cells stick together and block a blood vessel.

CAUSES

Every cell of the human body needs oxygen. One job of our blood is to bring the oxygen we breathe from our lungs to the different parts of our body. Round or donut-shaped red blood cells carry the oxygen in the blood and can move easily through our blood vessels.

Babies with sickle cell anemia (Hb SS) do not make enough healthy red blood cells. If your baby has Hb SS, his or her body makes some red blood cells that are a crescent or sickle shape rather than a round, donut shape. These unusually shaped cells do not last as long as normal red blood cells. This can lead to anemia (a low number of red blood cells).

The sickle or crescent shaped cells also tend to get stuck in blood vessels. When this happens, some parts of the body may not get enough blood. If red blood cells are not able move through the blood vessels, the body cannot get enough oxygen. This can cause many of the signs mentioned in Early Signs.

Hb SS is an autosomal recessive genetic condition. This means that a child must inherit two copies of the non-working gene for Hb SS, one from each parent, in order to have the condition. The parents of a child with an autosomal recessive condition each carry one copy of the non-working gene, but they typically do not show signs and symptoms of the condition. While having a child with Hb SS is rare, when both parents are carriers, they can have more than one child with the condition.

TREATMENT

Fluids

Dehydration occurs when an individual does not have enough fluid in his or her body. Babies with sickle cell anemia (Hb SS) need to make sure they get plenty of fluids because dehydration can increase the pain associated with Hb SS.

Medications

Children with Hb SS may need pain medication. Pain associated with Hb SS can usually be managed through over-the-counter painkillers like Tylenol. If it continues or becomes severe, your baby’s doctor may prescribe stronger medicines.

If your baby has Hb SS, he or she may develop repeated infections, especially during childhood. Your baby’s doctor may prescribe a daily dose of antibiotics to help prevent these infections.

Your baby’s doctor may also prescribe Hydroxyurea if your baby’s Hb SS is severe. This medication prevents anemia (low levels of red blood cells) by keeping the red blood cells from becoming sickle or crescent-shaped.

Blood Transfusions

Some children with Hb SS may need a blood transfusion because they do not have enough healthy red blood cells. In this procedure, blood from a healthy individual is given to someone with Hb SS.

Blood transfusions can also help prevent strokes. A stroke occurs when sickle-shaped red blood cells block a blood vessel that leads to the brain.

EXPECTED OUTCOMES

Treatments can help relieve the signs, symptoms, and complications of sickle cell anemia (Hb SS). Children who receive treatment for Hb SS can lead healthier lives than those without treatment.

Even with proper treatment, your child may still experience some signs and symptoms such as pain, anemia, and yellowish skin (jaundice). The more carefully you follow your child’s treatment plan, the healthier he or she can be.

It is important to screen for and treat Hb SS because, if left untreated, babies can die within their first year of life.