Abstract
Background: Rare diseases are an important population health issue and many promising therapies have been developed in recent years. In light of novel genetic treatments expected to significantly improve spinal muscular atrophy (SMA) patients’ quality of life and the urgent need for SMA newborn screening (NBS), new epidemiological data were needed to implement SMA NBS in Estonia. Objective: We aimed to describe the birth prevalence of SMA in the years 1996–2020 and to compare the results with previously published data. Methods: We retrospectively analyzed clinical and laboratory data of SMA patients referred to the Department of Clinical Genetics of Tartu University Hospital and its branch in Tallinn. Results: Fifty-seven patients were molecularly diagnosed with SMA. SMA birth prevalence was 1 per 8,286 (95% CI 1 per 6,130–11,494) in Estonia. Patients were classified as SMA type 0 (1.8%), SMA I (43.9%), SMA II (22.8%), SMA III (29.8%), and SMA IV (1.8%). Two patients were compound heterozygotes with an SMN1 deletion in trans with a novel single nucleotide variant NM_000344.3:c.410dup, p.(Asn137Lysfs*11). SMN2 copy number was assessed in 51 patients. Conclusion: In Estonia, the birth prevalence of SMA is similar to the median birth prevalence in Europe. This study gathered valuable information on the current epidemiology of SMA, which can guide the implementation of spinal muscular atrophy to the newborn screening program in Estonia.
Highlights
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder affecting approximately 1:10,000 live births, with a reported carrier frequency of 1:41 in Europe and 1:51 worldwide (Verhaart et al, 2017a; Wirth et al, 2020)
SMA is commonly caused by large deletions or, more rarely, pathogenic variants affecting the survival of motor neuron 1 gene (SMN1) (Lefebvre et al, 1995; Finkel et al, 2018; Mercuri et al, 2018)
We aimed to investigate the birth prevalence of SMA to guide the implementation of SMA newborn screening (NBS) soon in Estonia
Summary
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder affecting approximately 1:10,000 live births, with a reported carrier frequency of 1:41 in Europe and 1:51 worldwide (Verhaart et al, 2017a; Wirth et al, 2020). SMA is commonly caused by large deletions or, more rarely, pathogenic variants affecting the survival of motor neuron 1 gene (SMN1) (Lefebvre et al, 1995; Finkel et al, 2018; Mercuri et al, 2018). In light of novel genetic treatments expected to significantly improve spinal muscular atrophy (SMA) patients’ quality of life and the urgent need for SMA newborn screening (NBS), new epidemiological data were needed to implement SMA NBS in Estonia
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
