Serum hexosaminidase and ß-glucuronidase activities in infants: effects of age and sex

Abstract

We investigated the effect of age and sex on the serum activity of hexosaminidase (HEX) and ß-glucuronidase (BGLU) in 275 normal term infants aged 12 h to 12 months. Up to six weeks of life, HEX was significantly higher in boys (P£0.023). During the age period of 1-26 weeks, BGLU was also higher in boys, but differences were significant only at 2-6 and 7-15 weeks (P£0.016). The developmental pattern of HEX and BGLU was sex dependent. HEX activity increased in both sexes from 4-7 days of life, reaching a maximum of 1.4-fold the birth value at 2-6 weeks of age in boys (P<0.001) and a maximum of 1.6-fold at 7-15 weeks in girls (P<0.001). HEX activity gradually decreased thereafter, reaching significantly lower levels at 27-53 weeks than during the first three days of life in boys (P = 0.002) and the same level of this age interval in girls. BGLU increased in both sexes from 4-7 days of age, showing a maximum increase at 7-15 weeks (3.3-fold in boys and 2.9-fold in girls, both P<0.001). Then BGLU decreased in boys to a value similar to that observed at 4-7 days of age. In girls, BGLU remained elevated until the end of the first year of life. These results indicate a variation of HEX and BGLU activities during the first year of life and a sex influence on their developmental pattern. This observation should be considered in the diagnosis of GM 2 gangliosidosis and mucopolysaccharidosis type VII.

Reference Data on Neonatal Serum N-Acetyl-β-hexosaminidase Activity

“…The data about significant higher serum HEX activity (388.2 ± 113.0 nKat/L) of male neonates in comparison to female neonates (335.3 ± 110.0 nKat/L) ( p = 0.014 ∗ ) ( Figure 2(d) ) are in agreement with reports of other authors [ 29 – 32 ]. Differences in neonate serum HEX activity between males and females may depend on weight, but influence of sex hormones (mainly testosterone) may also be taken into consideration [ 31 ].…”

Early Onset of Lysosomal Storage Disease in a Murine Model of Mucopolysaccharidosis Type VII: Undegraded Substrate Accumulates in Many Tissues in the Fetus and Very Young MPS VII Mouse

“…Alternatively, HEXS, another form of the enzyme with similar properties, may be the enzyme involved in GAG degradation in utero, causing HEXB to not accumulate significantly until after birth [17]. The variability in HEXB specific activity we noted at single time points in the control mice could reflect differences in the ratio of male to female mice studied [26]. Nonetheless, the secondary elevation of HEXB, which is established during the first month of life, reflects increasing GAG storage and quantification of its decrease can serve as another marker of therapeutic response in the young MPS VII mouse.…”