Quantification of lysosphingomyelin and lysosphingomyelin-509 for the screening of acid sphingomyelinase deficiency

Table 1 Distribution of ASMD patients according to age at diagnosis, country, LysoSM, LysoSM509, and ASM activity

ID	Gender	Age at diagnosis	Country	LysoSM (nmoL/L)	LysoSM509 (nmoL/L)	ASM in DBS by MS/MS (nmoL/h/mL)^b	ASM in DBS or leukocytes by the ₁₄C method	Chitotriosidase levels (nmoL/h/mL)
1	Female	1.1	Brazil	3356	32,213	0.12	1^c	1475^e
2	Male	6.7	Brazil	750	32,767	n/a	0.6^c	738^e
3	Female	5.9	Brazil	547	19,826	n/a	0.6^c	2.3^e
4	Female	2.8	Brazil	539	22,573	n/a	0.20^d	944^e
5	Male	1	Brazil	1490	45,082	n/a	0.10^d	1334^e
6^a	Female	3.9	Brazil	400	21,812	0.05	n/a	n/a
7^a	Female	12.5	Brazil	361	17,333	0.06	n/a	n/a
8	Female	39.1	Brazil	840	65,404	0.08	n/a	356^f
9	Male	12.5	Brazil	577	42,215	0.21	n/a	290^f
10	Female	39.1	Brazil	697	36,031	0.26	1.1^c	125^f
11	Male	14.1	Brazil	692	32,365	n/a	0.2^c	429^e
12	Male	4.7	Ecuador	277	16,806	0.47	n/a	n/a
13	Female	2.7	Brazil	1244	22,747	0.06	0.7^c	290^f
14	Male	0.7	Brazil	790	32,988	n/a	0.5^c	Undetectable^f

n/a not available, DBS dried blood spots, ASM acid sphingomyelinase, ASMD acid sphingomyelinase deficiency
^aPatients 6 and 7 are siblings from a non-consanguineous family
^bASM cutoff for affected ASMD patients by MS/MS < 0.59 nmoL/h/mL
^cASM cutoff for affected ASMD patients in DBS < 4.8 nmoL/24 h/mL by the ₁₄C radioisotopic method
^dASM cutoff for affected ASMD patients in leukocytes < 0.74 nmoL/h/mg of protein by the ₁₄C radioisotopic method
^eReference range of chitotriosidase in plasma = 8.8–132 nmoL/h/mL
^fReference range of chitotriosidase in DBS = 0–44 nmoL/h/mL

ISSN: 1750-1172