Differential Diagnostics for ASMD in Patients Suspected to have GD

Objective

To demonstrate

of differential diagnosis

Primary diagnostic testing

Improve detection rate of potential

ASMD
Avoid diagnostic delays

A multicenter, prospective study

DBS testing

GBA enzyme activity

ASM enzyme activity

Genetic confirmatory testing

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

10-18 years

28 days to <10 years

>18 years

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

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.