Twelve-year review of galactosemia newborn screening in Taiwan: Evolving methods and insights.

Background: Galactosemia was introduced into Taiwan's routine newborn screening (NBS) program in 1985. This study presents a 12-year experience, emphasizing disease diagnosis and screening performance. Method: NBS for galactosemia utilized dried blood spot samples taken 48-72 h post-delivery, with total galactose (TGal) level as the primary marker. Newborns with critical TGal levels were referred immediately, while those with borderline TGal underwent a recall test. GALT activity measurement was applied simultaneously as the second-tier marker. Further confirmatory tests, such as whole exome sequencing (WES), were conducted upon referral. Results: From January 1st, 2011, to December 31st, 2022, 51 cases were identified from 817,906 newborns. Of these, nine individuals had persistently elevated TGal. Diagnoses included one case of GALT deficiency, one of GALM deficiency, and seven of GALE deficiencies. Notably, the classic galactosemia patient (GALT deficiency) presented with extreme high TGal and was referred to the hospital for diet management immediately. All affected patients were instructed to adopt a galactose-restricted diet. By the median age of 2.5 years, all exhibited normal development and liver function. Conclusion: The incidence of classical galactosemia and its variants is extremely low in Taiwan. Incorporating WES into NBS has improved our ability to detect various galactosemia forms, enriching our understanding of the genetic underpinnings. While these newly discovered forms often present with milder initial elevations in TGal, specific biochemical investigations and regular monitoring are essential to understanding the long-term implications and outcomes.

Late-onset symptomatic hyperprolactinemia in 6-pyruvoyl-tetrahydropterin synthase deficiency.

BACKGROUND: Tetrahydrobiopterin (BH4) deficiency caused by 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency is a rare disorder that is one of the major causes of hyperphenylalaninemia in Taiwan. METHODS: In this study, we reviewed the clinical courses of 12 adolescent and adult patients (7 females and 5 males) with PTPS deficiency. RESULTS: The patients were treated shortly after diagnosis through newborn screening with a combination of BH4, levodopa/carbidopa, and 5-OH-tryptophan. Their plasma phenylalanine and tyrosine levels were well controlled, and their prolactin levels were also decreased after treatment. However, their prolactin levels gradually rose as they grew into puberty, and at a current age of 27.5 [interquartile range (IQR 7.9)] years, five of the 12 patients had either highly elevated prolactin levels (> 100 ng/mL in one male patient, normal reference values, male < 11 ng/mL, female < 17 ng/mL) or symptoms, including irregular menstruation, amenorrhea, and breast swelling (in four female patients). The dosage of levodopa in these five patients (14.3 (IQR 3.0) mg/kg/day) was slightly higher than that in the other patients (p = 0.05). Magnetic resonance imaging studies did not reveal an increase in the size of the anterior pituitary gland, although a Rathke cleft cyst was found in one patient. Two patients received cabergoline treatment, which promptly lowered prolactin levels and relieved symptoms. CONCLUSIONS: Hyperprolactinemia is common in female patients with PTPS deficiency, especially after puberty. A long-acting dopamine agonist, such as cabergoline, may be a necessary adjunctive treatment for most patients with BH4 deficiency.

Aromatic l-amino acid decarboxylase deficiency in Taiwan.

Aromatic l-amino acid decarboxylase (AADC) deficiency is a rare inherited disorder that affects neurotransmitter biosynthesis. A DDC founder mutation c.714 + 4A > T (IVS6 + 4A > T) is prevalent in the Chinese population. This study investigated the epidemiology of AADC deficiency in Taiwan by analyzing data from National Taiwan University Hospital (NTUH), a central institution for diagnosing and treating the disease. From January 2000 to March 2023, 77 patients with AADC deficiency visited NTUH. Among them, eight were international patients seeking a second opinion, and another two had one or both non-Chinese parents; all others were ethnically Chinese. The c.714 + 4A > T mutation accounted for 85% of all mutated alleles, and 94% of patients exhibited a severe phenotype. Of the 77 patients, 31 received gene therapy at a mean age of 3.76 years (1.62-8.49) through clinical trials, and their current ages were significantly older than those of the remaining patients. Although the combined incidence of AADC deficiency in this study (1:66491 for 2004 and later) was lower than that reported in newborn screening (1:31997 to 1:42662), case surges coincided with the launch of clinical trials and the implementation of newborn screening. Currently, many young patients are awaiting for treatment.

Bedtime extended release cornstarch improves biochemical profile and sleep quality for patients with glycogen storage disease type Ia.

BACKGROUND: Patients with glycogen storage disease type Ia (GSDIa) are prone to hypoglycemia. Uncooked cornstarch (CS) is the treatment, but maintaining nighttime blood glucose levels is still difficult. METHODS: The study enrolled patients with GSDIa to investigate the benefits of bedtime extended release CS (ER-CS, Glycosade®) versus regular CS. The daytime CS schedule was not altered. A 7-day continuous glucose monitoring (CGM) was performed at the baseline and 12 weeks after using ER-CS. Biochemical profile, sleep quality (Pittsburgh Sleep Quality Index, PSQI), and quality of life (SF-36 questionnaire) were measured at the baseline and 24 weeks after using ER-CS. RESULTS: Nine patients (9 to 33 years of age) were enrolled. Compared with the baseline (80.0 ± 6.33 mg/dL), the 12-week evaluations revealed higher mean morning glucose levels (86.5 ± 8.26 mg/dL, p = 0.015). Twenty-four weeks after the use of bedtime ER-CS, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels both decreased (from 69.3 ± 77.8 to 41.1 ± 40.4 U/L and from 78.8 ± 99.6 to 37.8 ± 28.81 U/L, respectively, p = 0.013 for both analyses), and sleep and fasting time both elongated (from 7.8 ± 0.87 to 8.6 ± 1.02 h and from 6.5 ± 1.22 to 7.6 ± 1.02 h, respectively, p = 0.011 for both analyses). The mean PSQI score in the five adult patients decreased significantly (from 5.8 ± 1.29 to 3.0 ± 1.71, p = 0.042). CONCLUSION: This study provides evidence of clinically meaningful improvements by shifting only bedtime regular CS to ER-CS in patients with GSDIa. As ER-CS is considerably more expensive than regular CS, this approach presents a cost-effective alternative.

Blood Eosinophil Endotypes across Asthma and Chronic Obstructive Pulmonary Disease (COPD).

Background: Eosinophils were common inflammatory cells involved in the occurrence and development of various inflammatory diseases. Multiple recent studies have pointed to the increasingly important role of eosinophils in respiratory diseases. This article aims to compare the expression differences of blood eosinophil counts between asthma, chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap (ACO). Methods: Patients with asthma, COPD, and ACO who were seen in the First Affiliated Hospital of Guangzhou Medical University from January 2012 to June 2019 were included. We collected information such as age, gender, diagnosis, the eosinophil counts from the medical records. Moreover, the levels of 10 cytokines in the plasma of each group were detected by using the Meso Scale Discovery method. Results: We included 9787 patients with asthma, 15806 patients with COPD, and 831 ACO patients. From our results, it can be first found that eosinophil levels were age-related in the three diseases (asthma and ACO: p < 0.001; COPD: P = 0.001); in asthma and COPD, the number of eosinophils in males was more significant than that in females (asthma: p < 0.001; COPD: p = 0.012). Second, asthma patients had higher blood eosinophil counts than those with COPD and ACO (p < 0.001). Moreover, we found out that eosinophil levels were highly expressed in the stable group of all three diseases. Finally, we found that most cytokines in ACO patients showed a downward trend when the level of eosinophils was low, whereas the results were reversed in asthma patients; 7 cytokines had similar trends in COPD and ACO patients. Conclusions: In conclusion, eosinophils have their own unique endotypes in asthma, COPD, and ACO patients, which were reflected in the fluctuation of their levels and changes in cytokine secretion.

High incidence of null variants identified from newborn screening of X-linked adrenoleukodystrophy in Taiwan.

Background: Adrenoleukodystrophy (ALD) is an X-linked peroxisomal disorder caused by variants in the ABCD1 gene and can lead to Addison disease, childhood cerebral ALD, or adrenomyeloneuropathy. Presymptomatic hematopoietic stem cell transplantation is the only curative treatment for the disease and requires early detection through newborn screening (NBS) and close follow-up. Methods: An NBS program for ALD was performed by a two-tiered dried blood spot (DBS) lysophosphatidylcholine C26:0 (C26:0-LPC) concentration analysis. ABCD1 sequencing was eventually added as a third-tier test, and whole exome sequencing was used to confirm the diagnosis of all peroxisomal diseases. Affected newborns were followed-up for adrenal insufficiency and cerebral white matter abnormalities. Results: We identified 12 males and 10 females with ABCD1 variants, and 3 patients with Zellweger syndrome from 320,528 newborns. Eight (36.4%) ABCD1 variants identified in the current study were null variants, but there were no hotspots or founder effect. During a median follow-up period of 2.28 years, two (16.7%) male patients with ABCD1 variants developed Addison's disease. Extended family screening revealed one 28-year-old asymptomatic hemizygous father of a null variant (c.678delC). Among the three with Zellweger syndrome, one died at the age of 3 months, one showed developmental delay at the age of 1 year, and one was lost to follow-up. Conclusion: Screening for ALD has been added to the NBS program in Taiwan with a high degree of success. The screening algorithm revealed a high proportion of null variants in cases found by NBS in Taiwan, a subset of patients who may have earlier disease onset. We also demonstrate the feasibility of combining the diagnosis of ALD and other peroxisomal disorders into one screening algorithm.

Improved diagnosis of citrin deficiency by newborn screening using a molecular second-tier test.

BACKGROUND: Citrin deficiency is an autosomal recessive disorder caused by variants of the SLC25A13 gene. Although newborn screening (NBS) provides an opportunity for its early diagnosis and treatment, citrin deficiency detection rates remain lower than those estimated. METHODS: Before 2018, NBS for citrin deficiency was based on citrulline levels alone. In June 2018, a second-tier molecular test was implemented to detect 11 common variants of the SLC25A13 gene and improve the NBS detection rates. This study compares the incidence rates and costs before and after the second-tier implementation. RESULTS: Prior to 2018, five subjects were diagnosed via NBS, and 12 of 555,449 newborns screened were missed. In comparison, 11 subjects were diagnosed out of 198,071 newborns screened after 2018, and there were no false-negatives. The citrin deficiency detection rate increased from 1/32,673 to 1/18,006 after the second-tier test was implemented, with only a minimal increase in the total cost. The number of false-positive in our cohort was tolerable. Subjects with citrin deficiency may present with borderline elevated citrulline levels; these can remain slightly elevated or increase considerably on retest. Four patients (80%) detected prior to second-tier testing and six patients (55%) detected after it was implemented were identified based on the citrulline levels alone. However, at the time of second blood sampling, the normal citrulline level of five subjects did not exclude a citrin deficiency diagnosis. CONCLUSIONS: Our study shows that it is vital and cost-effective to employ second-tier molecular testing to improve the detection of citrin deficiency by NBS.

Asymptomatic ASS1 carriers with high blood citrulline levels.

INTRODUCTION: Citrullinemia Type 1 (CTLN1) is an autosomal recessive disorder caused by variants in the ASS1 gene. This study intends to clarify the etiology of false positives in newborn screening for citrullinemia. METHOD: Newborns who had elevated dried-blood spot citrulline levels were enrolled, and medical records were reviewed retrospectively. Common ASS1 variants were screened using high-resolution melting analysis. RESULT: Between 2011 and 2021, 130 newborns received confirmatory testing for citrullinemia, 4 were found to be patients for CTLN1; 11 were patients with citrin deficiency; and 49 newborns were confirmed to be carrying one pathogenic ASS1 variant. The incidence of CTLN1 was 1 in 188,380 (95% confidence interval: 1 in 73,258 to 1 in 484,416). All ASS1 variants studied in this cohort were located in exons 11 to 15, which encode the tetrameric interface regions of the ASS1 protein. Among 10 ASS1 carriers with elevated citrulline levels and complete sequence data, four (40%) revealed additional non-benign ASS1 variants; in contrast, only 2 of the 26 controls (7.7%), with normal citrulline levels, had additional ASS1 variants. CONCLUSION: Heterozygote ASS1 variants may lead to a mild elevation of blood citrulline levels: about 2-6 times the population mean. Molecular testing and family studies remain critical for precise diagnosis, genetic counseling, and management.

Clinical application of fractional exhaled nitric oxide and nasal nitric oxide levels for the assess eosinophilic inflammation of allergic rhinitis among children.

BACKGROUND: Allergic rhinitis is one of the most common nasal inflammatory diseases among children. Assessment of clinical symptoms, skin prick test and serum immunoglobulin E (IgE) are common methods used to diagnose allergic rhinitis and assess inflammation degree in clinical settings. However, via blood tests assess eosinophils inflammation is invasive, and may cause fear in children. It makes have burden of the diagnosis of allergic rhinitis. Nasal nitric oxide (nNO) and fractional exhaled nitric oxide (FeNO) are noninvasive, inexpensive, and can provide immediate results. These methods may therefore be preferable to assess the inflammation of allergic rhinitis. METHODS: This study was a retrospective analysis. We recruited 61 children with allergic rhinitis from November 2019 to March 2020. The participants were assessed using the FeNO and nNO tests. We also administered questionnaires and carried out traditional allergen and blood tests. We analyzed the relationship between diagnosis results and FeNO and nNO levels before and after the treatment of allergic rhinitis, to investigate the clinical application of FeNO and nNO levels for assess eosinophilic inflammation of allergic rhinitis in children. RESULTS: We observed a significant association both FeNO, nNO level with eosinophils, total IgE. In different levels of eosinophils (EOS), the correlation of detection parameters had obvious change. FeNO and nNO levels were obvious higher compared to pre-treatment. CONCLUSIONS: Using NO concentration can indicates the extent of allergic inflammation and can measure allergy treatment effects combine other influence indexes. The combined use of FeNO and nNO levels may be a useful method for assess the degree of eosinophilic inflammation of allergic rhinitis in children.

Extended-spectrum ß-lactamase-producing Escherichia coli bacteremia: Comparison of pediatric and adult populations.

BACKGROUND/PURPOSE: The prevalence of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli is increasing worldwide. This study investigated the clinical features and bacteriology of pediatric patients with ESBL-producing E. coli bacteremia and compared their characteristics with those of adult patients. METHODS: Clinical and laboratory data from all of the 41 patients aged ≤18 years diagnosed with E. coli bacteremia were collected over 5 years. Patients aged >18 years diagnosed with E. coli bacteremia, matched 1:1 for calendar time, were enrolled as the adult group. All E. coli isolates were tested for their blaCTX-M group and sequence type 131 (ST131). A novel seven-single nucleotide polymorphism-based clonotyping test was applied to detect the septatypes of each isolate. RESULTS: In the adult group, patients with ESBL-producing E. coli bacteremia had more previous hospitalizations and antimicrobial agent use than did those with non-ESBL-producing E. coli bacteremia, but these differences were not found in pediatric group. In the pediatric group, the proportion of isolates producing CTX-M group 9 was higher than that in the adult group (85.7% vs. 42.9%; p < 0.05). Among both groups, there were more E. coli ST131 in ESBL isolates in than there were non-ESBL isolates. The distribution of septatypes was more homogenous in ESBL-producing E. coli among the pediatric patients than among the adult patients. CONCLUSION: ST131 was the major clone causing E. coli bacteremia in both pediatric and adult populations. The pediatric population demonstrated a higher number of isolates producing CTX-M group 9 with more homogenous septatypes compared with the adult population.