Early Diagnosis of Fanconi-Bickel Syndrome and a Novel Mutation in SLC2A2 Gene

Fanconi-Bickel syndrome is a metabolic disease caused by mutations in SCL2A2 gene. Hepatic and renal glycogen storage, fasting hypoglycemia, and renal tubular dysfunction are characteristics of the disease that is usually diagnosed at 6-10 months of age. Here, we present a case of Fanconi-Bickel syndrome in a patient who was diagnosed at 47 days of age with the findings of glycosuria, hyperglycemia and an elevated level of alkaline phosphatase (ALP). The diagnosis was confirmed by identification of a new mutation in SLC2A2 gene and metabolic control was provided by a galactose-restricted high protein diet. A 27-day-old female patient was admitted with glycosuria. It was observed that she did not gain enough weight, had fat cheeks and hepatomegaly. Biochemical investigations revealed transaminase and ALP elevation. Fasting plasma glucose level was normal whereas postprandial glucose level was 198 mg/dL Urinalysis revealed 1+ protein and 3+ glucose. In follow-up, hyperglycemia started to be more evident, the ALP level decreased, compensated metabolic acidosis developed and the diagnosis of Fanconi-Bickel syndrome was assumed at 47 days of age. Under nutrition and oral replacement therapies good metabolic control and weight gain could be achieved. Postprandial hyperglycemia and glycosuria are early diagnostic clues for Fanconi-Bickel syndrome. Awareness of early findings and initiation of galactose-restricted high protein diet may provide metabolic control and prevent late complications

BNT162b2 COVID-19 vaccination elicited protective robust immune responses in pediatric patients with inborn errors of metabolism

IntroductionSARS-CoV-2 infection can lead to a life-threatening acute metabolic decompensation in children with inborn errors of metabolism (IEM), so vaccination is mandatory. However, IEMs can also impair innate or adaptive immunity, and the impact of these immune system alterations on immunogenicity and vaccine efficacy is still unknown. Here, we investigated humoral immune responses to the BNT162b2 mRNA COVID-19 vaccine and clinical outcomes in pediatric IEM patients.MethodsFifteen patients between 12-18 years of age with a confirmed diagnosis of IEM, and received BNT162b2 were enrolled to the study. Patients with an anti-SARS-CoV-2 IgG concentration >50 AU/mL before vaccination were defined as “COVID-19 recovered” whereas patients with undetectable anti-SARS-CoV-2 IgG concentration were defined as “COVID-19 naïve”. Anti-SARS-CoV-2 Immunoglobulin G (IgG) and SARS-CoV-2 neutralizing antibody (nAb) titers were measured to assess humoral immune response.ResultsAnti-SARS-CoV-2 IgG titers and nAb IH% increased significantly after the first dose. The increase in antibody titers after first and second vaccination remained significant in COVID-19 naïve patients. Complete anti-SARS-CoV-2 IgG seropositivity and nAb IH% positivity was observed in all patients after the second dose. Vaccination appears to be clinically effective in IEM patients, as none of the patients had COVID-19 infection within six months of the last vaccination.DiscussionHumoral immune response after two doses of BNT162b2 in pediatric IEM patients was adequate and the immune response was not different from that of healthy individuals