Infantile onset Sandhoff disease: clinical manifestation and a novel common mutation in Thai patients

BMC Pediatrics

Table 2 Biochemical and mutation data

Patient	Enzyme assay in plasma		HEXB mutation
Patient	Total HEX (% of normal range)^a	HEX-B activity (% of normal range)^b	% HEX-A/ total HEX^c	Zygosity	Base change	Amino acid change
1	21.9 (3.0%)	3.0 (1.1%)	89.0	homo	c.1652G>A	p.Cys551Tyr
2	70.2 (9.6%)	7.7 (2.7%)	89.0	homo	c.1652G>A	p.Cys551Tyr
3	48.9 (6.7%)	7.6 (2.6%)	84.5	homo	c.1652G>A	p.Cys551Tyr
4	33.1^d (4.1%)	NA	95.1^d	het het	c.1652G>A c.761 T>C	p.Cys551Tyr p.Leu254Ser
5	46.1 (6.3%)	2.6 (0.9%)	94.5	homo	c.1652G>A	p.Cys551Tyr

het heterozygous, homo homozygous
^a Total HEX reference range: 729 ± 225.6 nmol/hr./ml; % of normal range as compared to the according mean reference range
^b HEX-B activity reference range: 288.9 ± 59.1 nmol/hr./ml; % of normal range as compared to the according mean reference range
^c % HEX-A/total HEX reference range: 59.3 ± 6.3%
^d reference ranges for total enzyme activity and % HEX-A/total HEX activity were 801 ± 190 nmol/mg prot/hr. and 55–72%, respectively (National Taiwan University Hospital Laboratory)

ISSN: 1471-2431