Objective

To demonstrate benefits of differential diagnosis within primary diagnostic testing.
To improve detection rate of potential ASMD, avoid diagnostic delays.

A multicenter, prospective study

DBS testing

GBA enzyme activity
ASM enzyme activity

Positive Cases

Improve detection rate of potential
ASMD Avoid diagnostic delays

Results

Genetic confirmatory testing done for 5933 cases

SMPD1 gene sequencing for 1171 cases

GBA gene sequencing for 4762 cases

ASMD:GD varies by region

Overall, 1 out of 4 patients with suspected GD suffered from ASMD.

Overall, 51% of ASMD cases were newborns.

<28 days	28 days to <10 years
10-18 years	>18 yeras

5933 symptomatic cases showed decreased enzyme activities

227 distinct SMPD1 sequence variants identified

10 more frequent variants

Most of the cases with ASMD from the Middle East were newborns and with GD were adults.

Color by:

Gene-ID

Age group

GBA Adults (>18 years)

GBA Children (below 10 years)

GBA Children/adolescents (10–18 years)

GBA Newborns

SMPD1 Adults (>18 years)

SMPD1 Children (below 10 years)

SMPD1 Children/adolescents (10–18 years)

SMPD1 Newborns

Higher number of confirmed ASMD patients in Pakistan, Iraq, Turkey, and Iran

Egypt had the highest number of GD cases followed by Turkey, while Iraq had the highest number of ASMD cases.

Conclusion

Abbreviations

ASM: Acid sphingomyelinase; ASMD: Acid sphingomyelinase deficiency; DBS: Dried blood spots; GBA: Acid- -glucocerebrosidase; GD: Gaucher disease; KSA: Kingdom of Saudi Arabia; SMPD1: Sphingomyelin phosphodiesterase 1; UAE: United Arab Emirates.

Reference

Oliva P, Schwarz M, Mechtler TP, et al. Importance to include differential diagnostics for acid sphingomyelinase deficiency (ASMD) in patients suspected to have to Gaucher disease. Mol Genet Metab. 2023;139(1):107563.