Recently, lyso-globotriaosylsphingosine (lyso-Gb3) was found to be elevated in plasma of treatment naive male patients and some female patients with Fabry Disease (FD). This study tested whether lyso-Gb3 could be analyzed in dried blood spots (DBS) from filter cards and whether concentrations are elevated in newborn infants with FD. Lyso-Gb3 concentrations were analyzed in DBS following extraction using a novel HPLC-mass spectrometry (MS)/MS method. Lyso-Gb3 levels in DBS were above the lower limit of quantitation (0.28 ng/mL) in 5/17 newborn FD infants (16 males; range: 1.02-8.81 ng/mL), but in none of the newborn controls, in all 13 patients (4 males) with classic FD (range: 2.06-54.1 ng/mL), in 125/159 Taiwanese individuals with symptomatic or asymptomatic FD who carry the late onset alpha-galactosidase A (GLA) mutation c.936+919G>A (IVS4+919G>A) (3.75+/-0.69 ng/mL; range: 0.418-3.97 ng/mL) and in 20/29 healthy controls (0.77+/-0.24 ng/mL; range: 0.507-1.4 ng/mL). The HPLC-MS/MS method for analysis of lyso-Gb3 is robust and yields reproducible results in DBS in patients with FD. However, concentrations of lyso-Gb3 were below the limit of quantitation in most newborn infants with FD rendering this approach not suitable for newborn screening. In addition, most females with the late onset mutation have undetectable lyso-Gb3 concentrations.
Adolescent ; Adult ; Blood Chemical Analysis/*methods ; Child ; Chromatography, High Pressure Liquid ; *Dried Blood Spot Testing ; Fabry Disease/blood/diagnosis ; Female ; Glycolipids/*blood ; Humans ; Infant, Newborn ; Male ; Sphingolipids/*blood ; Tandem Mass Spectrometry ; Young Adult

Objective: aaWilson’s disease (WD) is a rare genetic disorder of copper metabolism, and longitudinal follow-up studies are limited. We performed a retrospective analysis to determine the clinical characteristics and long-term outcomes in a large WD cohort. Methods: aaMedical records of WD patients diagnosed from 2006–2021 at National Taiwan University Hospital were retrospectively evaluated for clinical presentations, neuroimages, genetic information, and follow-up outcomes. Results: aaThe present study enrolled 123 WD patients (mean follow-up: 11.12 ± 7.41 years), including 74 patients (60.2%) with hepatic features and 49 patients (39.8%) with predominantly neuropsychiatric symptoms. Compared to the hepatic group, the neuropsychiatric group exhibited more Kayser-Fleischer rings (77.6% vs. 41.9%, p < 0.01), lower serum ceruloplasmin levels (4.9 ± 3.9 vs. 6.3 ± 3.9 mg/dL, p < 0.01), smaller total brain and subcortical gray matter volumes (p < 0.0001), and worse functional outcomes during follow-up (p = 0.0003). Among patients with available DNA samples (n = 59), the most common mutations were p.R778L (allelic frequency of 22.03%) followed by p.P992L (11.86%) and p.T935M (9.32%). Patients with at least one allele of p.R778L had a younger onset age (p = 0.04), lower ceruloplasmin levels (p < 0.01), lower serum copper levels (p = 0.03), higher percentage of the hepatic form (p = 0.03), and a better functional outcome during follow-up (p = 0.0012) compared to patients with other genetic variations. Conclusion aaThe distinct clinical characteristics and long-term outcomes of patients in our cohort support the ethnic differences regarding the mutational spectrum and clinical presentations in WD.