Newborn screening for Fabry disease in the north-west of Spain

Fabry disease is an X-linked lysosomal storage disorder caused by the impairment of α-galactosidase A. Enzyme replacement therapy is available to treat patients, who often experience delayed diagnosis. A newborn screening for Fabry disease was performed to study the prevalence of the pathology and to evaluate the possibility to implement the test in systematic screenings. We collected 14,600 dried blood spot samples (7575 males and 7025 females) and carried out a diagnostic study by fluorometric measurement of α-galactosidase A enzymatic activity and GLA gene sequencing. We detected one patient with a mutation in GLA associated with classical Fabry Disease (M290I), ten subjects carrying genetic variants of uncertain diagnosis (S126G, R118C, A143T), and a girl with the non-characterized variant F18Y, which was not previously described. Additional 25 samples presented nucleotide substitutions described as polymorphisms (D313Y, rs2071225, and rs2071397). The estimated prevalence for Fabry disease in north-western Spanish males is of 0.013%.

These results confirm that the prevalence of Fabry disease is underestimated and systematic screening is feasible; however, further characterization of variants of uncertain clinical significance is necessary to establish protocols of patients' management. What is Known: • Fabry disease is a rare disease of delayed diagnosis, whose prevalence is underestimated. However, early diagnosis is important for better efficiency of the current available treatment. What is New: • This newborn screening for Fabry disease performed on Spanish population reveals a prevalence of genetic alterations in GLA of 0.1% in males (0.013% with classic Fabry disease) and also characterizes these modifications in order to discriminate between pathogenic mutations and genetic variants of unknown significance.