The State of Florida uses the Beutler fluorescent spot test for quantitative measurement of GALT enzyme activity. This enzyme splits lactose into glucose and galactose for subsequent metabolism. The fluorescence test identifies babies deficient in this enzyme, but it can also identify babies with low but not disease-causing enzyme activity; the most common cause for this is the Duarte mutation variant, discussed in this video developed by our division and posted on YouTube.
The biotinidase enzyme is crucial in recycling biotin, a vitamin-like compound, that is an important cofactor for several crucial metabolizing enzymes. This video, developed by our division, discusses the general issue of biotinidase deficiency.
The State of Florida uses an enzymatic method to determine quantitative biotinidase enzyme activity and, like the determination of GALT enzyme activity, some babies can be identified to have low but not disease-causing enzyme activity; most commonly due to high prevalence of a variant mutation, reviewed in this video.