Screening for sickle cell disease is now routine for newborns

The newborn screening program has been in existence since 1972. It is characterized by medical biology tests, which are carried out in each region by a regional center for newborn screening (CRDN) attached to a university hospital (CHU) in conjunction with the regional health agencies (ARS).

Newborn screening is done by taking drops of blood from a blotter after the newborn has had a small stitch to the heel. It is systematically proposed and carried out after agreement of the parents. The procedure is done most often in the maternity ward, sometimes at home, within 3 days of birth. Results are communicated to parents only if there is a problem.

Following the recommendations of the High Health Authority, the sickle cell disease, the most common genetic disease among those detected at birth, will be screened systematically in all newborns, according to a decree published in the Official Journal of 3 August 2024. Previously, her screening was subject to conditions.

What is sickle cell disease and what are the symptoms?

The sickle cell disease, also known as sickle cell anemia, is an inherited genetic disorder affecting red blood cells (or red blood cells). It is characterized by hemoglobin abnormality, the main protein in the red blood cell.

Symptoms of the disease vary and depend not only on age but also on the severity of sickle cell disease.

In the first few months, infants are usually asymptomatic because they benefit from having hemoglobin from the fetus, the form of hemoglobin produced in the fetus during the in utero period, which is not mutated. The first complications occur from about 3 months of age with painful attacks and acute anemia that can cause shortness of breath and fatigue. This disease is also responsible for an increased sensitivity to bacterial infections (pneumonia, meningitis or septicemia...).

In toddlers, the attack usually causes painful swelling of the hands and feet (hand-foot syndrome).

What are the other 12 serious childhood illnesses currently being screened for?

Diseases sought by the screening are:

• the phenylketonuria : A genetic disorder caused by a lack of an enzyme that transforms the phenylalanine in the diet. Without treatment, it can cause severe mental retardation and neuropsychiatric complications;
• thecongenital hypothyroidism : A disease in which the thyroid gland does not produce enough thyroid hormones. If untreated, its dysfunction affects major body functions, including severe mental retardation;
• thecongenital hyperplasia adrenal glands: a genetic defect in how the adrenal glands work. Without treatment, it can cause severe, sometimes fatal acute dehydration and impaired development of sexual organs;
• the cystic fibrosis : A genetic disease that causes severe and repeated respiratory infections and digestive complications. Early management may help establish procedures to ensure good nutritional status of the child, help clear bronchial secretions, prevent infections, and treat them.
• the Medium-Chain-Acyl-CoA Dehydrogenase (MCAD) deficiency : A disease that makes it difficult for the body to use fat as an energy source. Without treatment, it can cause comas, which may last until the child dies;
• thehomocystinuria : A genetic disease related to the lack of an enzyme called cystathionine beta-synthase, which causes the build-up of homocysteine that is toxic to the body. Without treatment, it can damage the eyes, skeleton, vascular system, nervous system, and sometimes developmental delay;
• the leucinosis or “maple syrup odor” urine disease : a genetic disease related to the deficiency of an enzyme called ‘branched chain alpha-keto acid dehydrogenase’. Without treatment, people have rapid onset of feeding difficulties, prolonged sleep, vomiting, and then neurologic abnormalities, abnormal movements, and respiratory failure
• the tyrosinemia type 1 : A genetic disease related to the lack of the liver enzyme ‘fumaryl acetoacetate hydrolase’ which allows normal processing of proteins in food. Without proper diet and treatment, toxic waste products accumulate in the body and severely damage the liver, kidneys, and nervous system;
• theisovaleric aciduria : a genetic disease, also known as isovaleric acidemia, which is linked to the lack of an enzyme, isovaleryl-CoA dehydrogenase, which is responsible in the absence of an appropriate diet for acute disorders at birth (vomiting, convulsions) or later (growth and/or development retardation);
• theglutaric aciduria type 1 : a genetic disease related to the absence or insufficient function of an enzyme, ‘glutaryl CoA-dehydrogenase’. In the absence of a special diet, it causes accumulation of toxic substances that cause acute neurologic disorders in infants;
• the long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency : a genetic disease related to the absence or insufficiency of this enzyme. Without appropriate treatment and diet, hypoglycemia, liver damage, heart and nerve disorders develop in early childhood;
• the primary carnitine deficiency : genetic disease linked to the deficiency of the carnitine transporter. If carnitine is not given, this deficiency causes heart damage in early childhood, often associated with hypotonia, failure to thrive, recurrent hypoglycaemic attacks, and/or coma.

The number of diseases screened is likely to increase depending on the High Health Authority’s advice on new screenings.

The program is complemented by screening for permanent deafness of the newborn.

Screening for 13 rare diseases adds to previously diagnosed conditions.