The highest frequency of<unk>  is found in tropical regions, particularly sub-Saharan Africa, tribal regions of India, and the Middle East. Migration of substantial populations from these high-prevalence areas to low-prevalence countries in Europe has dramatically increased in recent decades and in some European countries,<unk>  has now overtaken more familiar genetic conditions such as haemophilia and cystic fibrosis. In 2015, it resulted in about 114,800 deaths.<unk>  occurs more commonly among people whose ancestors lived in tropical and subtropical sub-Saharan regions where malaria is or was common. Where malaria is common, carrying a single<unk>  cell allele (trait) confers a heterozygote advantage; humans with one of the two alleles of<unk>  show less severe symptoms when infected with malaria. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Africa Three-quarters of<unk>  cell cases occur in Africa. A recent WHO report estimated that around 2% of newborns in Nigeria were affected by<unk>  cell anaemia, giving a total of 150,000 affected children born every year in Nigeria alone. The carrier frequency ranges between 10 and 40% across equatorial Africa, decreasing to 1–2% on the North African coast and <1% in South Africa. Studies in Africa show a significant decrease in infant mortality rate, ages 2–16 months, because of the<unk>  cell trait. This happened in areas of predominant malarial cases. Uganda has the fifth-highest<unk>  burden in Africa. One study indicates that 20 000 babies per year are born with<unk>  with the<unk>  cell trait at 13·3% and with<unk>  0·7%. + Country Population(2020) Subregion % of Prevalence Prevalence Incidence Angola 32,866,272 Middle Africa 0.09375 3,081,213 14,869 Cameroon 26,545,863 Middle Africa 0.117 3,105,866 11,826 DR Congo 89,561,403 Middle Africa 0.1163333333 10,418,977 65,536 Ghana 31,072,940 Western Africa 0.09375 2,913,088 9,588 Guinea 13,132,795 Western Africa 0.139375 1,830,383 8,907 Niger 24,206,644 Western Africa 0.07025 1,700,517 8,756 Nigeria 206,139,589 Western Africa 0.1286666667 26,523,294 150,000 Tanzania 59,734,218 Eastern Africa 0.0545 3,255,515 19,585 Uganda 45,741,007 Eastern Africa 0.07025 3,213,306 17,936 Zambia 18,383,955 Eastern Africa 0.082 1,507,484 9,958 Algeria 43,851,044 Northern Africa 0.029 1,271,680 6,624 Benin 12,123,200 Western Africa 0.1286666667 1,559,852 8,125 Botswana 2,351,627 Southern Africa 0.029 68,197 355 Burkina Faso 20,903,273 Western Africa 0.07025 1,468,455 7,649 Burundi 11,890,784 Eastern Africa 0.023 273,488 1,425 Cabo Verde 555,987 Western Africa 0.023 12,788 67 Central African Republic 4,829,767 Middle Africa 0.082 396,041 2,063 Chad 16,425,864 Middle Africa 0.0585 960,913 5,005 Comoros 869,601 Eastern Africa 0.023 20,001 104 Congo 5,518,087 Middle Africa 0.1615 891,171 4,642 Côte d'Ivoire 26,378,274 Western Africa 0.07025 1,853,074 9,652 Djibouti 988,000 Eastern Africa 0.023 22,724 118 Egypt 102,334,404 Northern Africa 0.029 2,967,698 15,458 Equatorial Guinea 1,402,985 Middle Africa 0.181 253,940 1,323 Eritrea 3,546,421 Eastern Africa 0.023 81,568 425 Eswatini 1,160,164 Southern Africa 0.023 26,684 139 Ethiopia 114,963,588 Eastern Africa 0.029 3,333,944 17,366 Gabon 2,225,734 Middle Africa 0.181 402,858 2,098 Gambia 2,416,668 Western Africa 0.082 198,167 1,032 Guinea-Bissau 1,968,001 Western Africa 0.035 68,880 359 Kenya 53,771,296 Eastern Africa 0.04675 2,513,808 13,094 Lesotho 2,142,249 Southern Africa 0.023 49,272 257 Liberia 5,057,681 Western Africa 0.07025 355,302 1,851 Libya 6,871,292 Northern Africa 0.029 199,267 1,038 Madagascar 27,691,018 Eastern Africa 0.04675 1,294,555 6,743 Malawi 19,129,952 Eastern Africa 0.035 669,548 3,488 Mali 20,250,833 Western Africa 0.082 1,660,568 8,650 Mauritania 4,649,658 Western Africa 0.04675 217,372 1,132 Mauritius 1,271,768 Eastern Africa 0.023 29,251 152 Morocco 36,910,560 Northern Africa 0.029 1,070,406 5,576 Mozambique 31,255,435 Eastern Africa 0.035 1,093,940 5,698 Namibia 2,540,905 Southern Africa 0.03883333333 98,672 514 Rwanda 12,952,218 Eastern Africa 0.035 453,328 2,361 Sao Tome & Principe 219,159 Middle Africa 0.181 39,668 207 Senegal 16,743,927 Western Africa 0.07025 1,176,261 6,127 Seychelles 98,347 Eastern Africa 0.023 2,262 12 Sierra Leone 7,976,983 Western Africa 0.1615 1,288,283 6,711 Somalia 15,893,222 Eastern Africa 0.029 460,903 2,401 South Africa 59,308,690 Southern Africa 0.029 1,719,952 8,959 South Sudan 11,193,725 Eastern Africa 0.04675 523,307 2,726 Sudan 43,849,260 Northern Africa 0.03883333333 1,702,813 8,870 Togo 8,278,724 Western Africa 0.09375 776,130 4,043 Tunisia 11,818,619 Northern Africa 0.023 271,828 1,416 Zimbabwe 14,862,924 Eastern Africa 0.035 520,202 2,710 Total 1,338,826,604 Africa 91,868,664 495,726 United States The number of people with the<unk>  in the United States is about 100,000 (one in 3,300), mostly affecting Americans of sub-Saharan African descent. In the United States, about one out of 365 African-American children and one in every 16,300 Hispanic-American children have<unk>  cell anaemia. The life expectancy for men with<unk>  is approximately 42 years of age while women live approximately six years longer. An additional 2 million are carriers of the<unk>  cell trait. Most infants with<unk>  born in the United States are identified by routine neonatal screening. As of 2016 all 50 states include screening for<unk>  as part of their newborn screen. The newborn's blood is sampled through a heel-prick and is sent to a lab for testing. The baby must have been eating for a minimum of 24 hours before the heel-prick test can be done. Some states also require a second blood test to be done when the baby is two weeks old to ensure the results.<unk>  cell anemia is the most common genetic disorder among African Americans. Approximately 8% are carriers and 1 in 375 are born with the<unk> . Patient advocates for<unk>  have complained that it gets less government and private research funding than similar rare<unk> s such as cystic fibrosis, with researcher Elliott Vichinsky saying this shows racial discrimination or the role of wealth in health care advocacy. France As a result of population growth in African-Caribbean regions of overseas France and immigration from North and sub-Saharan Africa to mainland France,<unk>  has become a major health problem in France.<unk>  has become the most common genetic<unk>  in the country, with an overall birth prevalence of one in 2,415 in metropolitan France, ahead of phenylketonuria (one in 10,862), congenital hypothyroidism (one in 3,132), congenital adrenal hyperplasia (one in 19,008) and cystic fibrosis (one in 5,014) for the same reference period. Since 2000, neonatal screening of<unk>  has been performed at the national level for all newborns defined as being "at-risk" for<unk>  based on ethnic origin (defined as those born to parents originating from sub-Saharan Africa, North Africa, the Mediterranean area (South Italy, Greece, and Turkey), the Arabic peninsula, the French overseas islands, and the Indian subcontinent). United Kingdom In the United Kingdom, between 12,000 and 15,000 people are thought to have<unk>  with an estimated 250,000 carriers of the condition in England alone. As the number of carriers is only estimated, all newborn babies in the UK receive a routine blood test to screen for the condition. Due to many adults in high-risk groups not knowing if they are carriers, pregnant women and both partners in a couple are offered screening so they can get counselling if they have the<unk>  cell trait. In addition, blood donors from those in high-risk groups are also screened to confirm whether they are carriers and whether their blood filters properly. Donors who are found to be carriers are then informed and their blood, while often used for those of the same ethnic group, is not used for those with<unk>  who require a blood transfusion. Middle East In Saudi Arabia, about 4.2% of the population carry the<unk>  cell trait and 0.26% have<unk> . The highest prevalence is in the Eastern province, where approximately 17% of the population carry the gene and 1.2% have<unk> . In 2005, Saudi Arabia introduced a mandatory premarital test including HB electrophoresis, which aimed to decrease the incidence of<unk>  and thalassemia. In Bahrain, a study published in 1998 that covered about 56,000 people in hospitals in Bahrain found that 2% of newborns have<unk> , 18% of the surveyed people have the<unk>  cell trait, and 24% were carriers of the gene mutation causing the<unk> . The country began screening of all pregnant women in 1992 and newborns started being tested if the mother was a carrier. In 2004, a law was passed requiring couples planning to marry to undergo free premarital counseling. These programs were accompanied by public education campaigns. India and Nepal<unk>  is common in some ethnic groups of central India, where the prevalence has ranged from 9.4 to 22.2% in endemic areas of Madhya Pradesh, Rajasthan, and Chhattisgarh. It is also endemic among Tharu people of Nepal and India; however, they have a sevenfold lower rate of malaria despite living in a malaria infested zone. Caribbean Islands In Jamaica, 10% of the population carry the<unk>  cell gene, making it the most prevalent genetic disorder in the country.
Sickle cell disease
Glucose-6-phosphate dehydrogenase deficiency
Sickle cell trait
Avascular necrosis
Primary hyperoxaluria
Sick cell syndrome
Thalassemia
Hawkinsinuria