The Valencian Community has officially included the detection of Spinal muscular atrophy (AME) in the newborn screening program thanks to the famous “heel test”, after months of studies and pilot projects which demonstrated its viability and profitability. This measure, … which responds to a historic request, places the Valencian Community as a national reference in the prevention of serious neuromuscular diseases.
SMA is a rare genetic condition that causes degeneration of motor neurons, causing weakness and progressive muscle atrophy. Its impact is estimated at 1 in 10,000 live birthsand more than 95% of cases are due to the absence of a key fragment of the gene that keeps motor neurons healthy (exon 7 of the SMN1 gene). Detecting it before symptoms appear is crucial, because current treatments modify the course of the disease, especially if they are administered in the pre-symptomatic phase.
Screening is carried out with the same dried blood sample obtained by heel perforation between 24 and 72 hours of life. Analysis identifies a homozygous deletion of the SMN1 gene by real-time PCR. A positive result activates an urgent protocol which consists of confirmation of the diagnosis in less than 10 days and referral to the Hospital Universitari i Politècnic La Fe, which is a reference center for rare neuromuscular diseases.
Currently, three therapies are approved and administered at La Fe: Nusinersen (intrathecal administration, i.e. lumbar puncture), Risdiplam (oral) and Onasemnogene abeparvovec (gene therapy). These options have transformed the prognosis of SMA, as they allow babies diagnosed early to reach motor milestones unthinkable without treatment.
Previous investigations
The Valencian Community was a pioneer in Spain by launching a pilot project in 2022 to screen some 40,000 newborns per year in public and private hospitals. In three years, it enabled the presymptomatic diagnosis of three babies, who immediately accepted treatment with the aim of avoiding serious complications.
After this pilot test, the protocol now signed, with the agreement of the General Directorate of Public Health, Hospital Care, Pharmacy and the multidisciplinary team of La Fe Hospital, establishes the procedures for sample collection, genetic confirmation, communication to families and genetic counseling. The goal is to ensure a rapid and coordinated response that maximizes the therapeutic window.
In addition to SMA, the detection of four other pathologies has also been integrated into the heel test: isovaleric acidemia (a disorder in which toxic substances accumulate that can cause vomiting, convulsions and neurological damage), B-ketothiolase deficiency (makes the blood acidic and is life-threatening), 30H 3metolglutaric acidemia (without early diagnosis, it can cause hypoglycemia and insufficiency liver) and trifunctional protein deficiency (generates muscle weakness, heart problems and risk of death in infants).
All of these diseases are inborn errors of metabolism and, if not diagnosed in the first days of life, can trigger severe metabolic crises, irreversible neurological damage, and even death.
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