Is sickle Gene mutation

Which of the following mutations is the most likely cause of sickle cell anemia?

Sickle cell disease affects millions of people worldwide. It is most common among people whose ancestors come from Africa; Mediterranean countries such as Greece, Turkey, and Italy; the Arabian Peninsula; India; and Spanish-speaking regions in South America, Central America, and parts of the Caribbean.

Sickle cell disease is the most common inherited blood disorder in the United States, affecting an estimated 100,000 Americans. The disease is estimated to occur in 1 in 500 African Americans and 1 in 1,000 to 1,400 Hispanic Americans.

Causes

Mutations in the HBB gene cause sickle cell disease. The HBB gene provides instructions for making one part of hemoglobin. Hemoglobin

consists of four protein subunits, typically, two subunits called alpha-globin and two subunits called beta-globin. The HBB gene provides instructions for making beta-globin. Various versions of beta-globin result from different mutations in the HBB gene. One particular HBB gene mutation produces an abnormal version of beta-globin known as hemoglobin S [HbS]. Other mutations in the HBB gene lead to additional abnormal versions of beta-globin such as hemoglobin C [HbC] and hemoglobin E [HbE]. HBB gene mutations can also result in an unusually low level of beta-globin; this abnormality is called beta thalassemia.

In people with sickle cell disease, at least one of the beta-globin subunits in hemoglobin is replaced with hemoglobin S. In sickle cell anemia [also called homozygous sickle cell disease], which is the most common form of sickle cell disease, hemoglobin S replaces both beta-globin subunits in hemoglobin. In other types of sickle cell disease, just one beta-globin subunit in hemoglobin is replaced with hemoglobin S. The other beta-globin subunit is replaced with a different abnormal variant, such as hemoglobin C. For example, people with sickle-hemoglobin C [HbSC] disease have hemoglobin molecules with hemoglobin S and hemoglobin C instead of beta-globin. If mutations that produce hemoglobin S and beta thalassemia occur together, individuals have hemoglobin S-beta thalassemia [HbSBetaThal] disease.

Abnormal versions of beta-globin can distort red blood cells into a sickle shape. The sickle-shaped red blood cells die prematurely, which can lead to anemia. Sometimes the inflexible, sickle-shaped cells get stuck in small blood vessels and can cause serious medical complications.

Learn more about the gene associated with Sickle cell disease

Inheritance

This condition is inherited in an autosomal recessive pattern

, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Other Names for This Condition

HbS disease
Hemoglobin S disease
SCD
Sickle cell disorders
Sickling disorder due to hemoglobin S

Additional Information & Resources

Genetic Testing Information

Genetic Testing Registry: Hb SS disease

Genetic and Rare Diseases Information Center

Sickle cell anemia

Patient Support and Advocacy Resources

Disease InfoSearch
National Organization for Rare Disorders [NORD]

Research Studies from ClinicalTrials.gov

ClinicalTrials.gov

Catalog of Genes and Diseases from OMIM

SICKLE CELL ANEMIA

Scientific Articles on PubMed

PubMed

References

Ashley-Koch A, Yang Q, Olney RS. Sickle hemoglobin [HbS] allele and sickle cell disease: a HuGE review. Am J Epidemiol. 2000 May 1;151[9]:839-45. doi: 10.1093/oxfordjournals.aje.a010288. Citation on PubMed
Gladwin MT, Sachdev V, Jison ML, Shizukuda Y, Plehn JF, Minter K, Brown B, Coles WA, Nichols JS, Ernst I, Hunter LA, Blackwelder WC, Schechter AN, Rodgers GP, Castro O, Ognibene FP. Pulmonary hypertension as a risk factor for death in patients with sickle cell disease. N Engl J Med. 2004 Feb 26;350[9]:886-95. doi: 10.1056/NEJMoa035477. Citation on PubMed
Powars DR, Chan LS, Hiti A, Ramicone E, Johnson C. Outcome of sickle cell anemia: a 4-decade observational study of 1056 patients. Medicine [Baltimore]. 2005 Nov;84[6]:363-376. doi: 10.1097/01.md.0000189089.45003.52. Citation on PubMed
Schnog JB, Duits AJ, Muskiet FA, ten Cate H, Rojer RA, Brandjes DP. Sickle cell disease; a general overview. Neth J Med. 2004 Nov;62[10]:364-74. Citation on PubMed
Serjeant GR. The emerging understanding of sickle cell disease. Br J Haematol. 2001 Jan;112[1]:3-18. doi: 10.1046/j.1365-2141.2001.02557.x. No abstract available. Citation on PubMed
Stuart MJ, Nagel RL. Sickle-cell disease. Lancet. 2004 Oct 9-15;364[9442]:1343-60. doi: 10.1016/S0140-6736[04]17192-4. Citation on PubMed
Vichinsky E. New therapies in sickle cell disease. Lancet. 2002 Aug 24;360[9333]:629-31. doi: 10.1016/S0140-6736[02]09776-3. Citation on PubMed
Vichinsky EP. Pulmonary hypertension in sickle cell disease. N Engl J Med. 2004 Feb 26;350[9]:857-9. doi: 10.1056/NEJMp038250. No abstract available. Citation on PubMed

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What mutations causes sickle

Sickle cell disease [SCD] is a genetic disorder caused by a mutation in both copies of a person's HBB gene. This gene encodes a component of hemoglobin, the oxygen-carrying protein in red blood cells. The mutation causes hemoglobin molecules to stick together, creating sickle-shaped red blood cells.

Is sickle

We now report an uncommon beta-thalassemia gene that contains a deletion of this nucleotide. Thus, one mutation [GAG leads to GTG] produces sickle-cell anemia, while the other [GAG leads to GG] eliminates beta-globin production.

What does the mutation for sickle

Normal hemoglobin [left] and hemoglobin in sickled red blood cells [right] look different; the mutation in the DNA slightly changes the shape of the hemoglobin molecule, allowing it to clump together.