Neonatal Screening for Congenital Metabolic and Endocrine Disorders–Results From Germany for the Years 2006–2018

Clinical outcomes of patients with mut-type methylmalonic acidemia identified through expanded newborn screening in China

BACKGROUND

Isolated methylmalonic acidemia, an autosomal recessive disorder of propionate metabolism, is usually caused by mutations in the methylmalonyl-CoA mutase gene (mut-type). Because no universal consensus was made on whether mut-type methylmalonic acidemia should be included in newborn screening (NBS), we aimed to compare the outcome of this disorder detected by NBS with that detected clinically and investigate the influence of NBS on the disease course.

DESIGN & METHODS

In this study, 168 patients with mut-type methylmalonic acidemia diagnosed by NBS were compared to 210 patients diagnosed after disease onset while NBS was not performed. Clinical data of these patients from 7 metabolic centers in China were analyzed retrospectively, including initial manifestations, biochemical metabolites, the responsiveness of vitamin B12 therapy, and gene variation, to explore different factors on the long-term outcome.

RESULTS

By comparison of the clinically-diagnosed patients, NBS-detected patients showed younger age at diagnosis, less incidence of disease onset, better responsiveness of vitamin B12, younger age at start of treatment, lower levels of biochemical features before and after treatment, and better long-term prognosis (P < 0.01). Onset of disease, blood C3/C2 ratio and unresponsiveness of vitamin B12 were more positively associated with poor outcomes of patients whether identified by NBS. Moreover, the factors above as well as older age at start of treatment were positively associated with mortality.

CONCLUSIONS

This research highly demonstrated NBS could prevent major disease-related events and allow an earlier treatment initiation. As a key prognostic factor, NBS is beneficial for improving the overall survival of infants with mut-type methylmalonic acidemia.

Incidence and associated risk factors of congenital hypothyroidism among newborns in Hainan, China: a retrospective study

OBJECTIVES

This study aims to investigate the incidence and risk factors of congenital hypothyroidism (CH) in newborns in Hainan Province, China, to provide a reference for early and effective prevention strategies.

METHODS

Newborns born in Hainan Province from 2017 to 2021 were the subjects of this study. Time-resolved immunofluorescence was used for initial screening and chemiluminescence for confirmatory diagnosis. Based on the diagnosis, newborns were classified into CH and non-CH groups. Statistical analysis was conducted on the initial screening and confirmed CH cases in newborns in Hainan Province, and potential risk factors for CH were explored.

RESULTS

From 2017 to 2021, a total of 585,886 newborns were screened, revealing 6,856 initial positive results, 614 positive rescreens, and 420 confirmed CH cases, yielding an incidence rate of 1/1,395 (420/585,886). The annual initial positive screening rate of newborns in Hainan Province showed a rising trend from 2017 to 2021 (p=0.000). No significant differences were found regarding gender (p=0.400) and ethnicity (p=0.836). Multivariate logistic regression analysis indicated that residing in coastal areas, especially those with salt fields (OR=2.151, 95 % CI: 1.364-3.390), was risk factors for the development of CH in newborns.

CONCLUSIONS

The incidence of CH in newborns showed a year-on-year increase in Hainan Province from 2017 to 2021. Residing in coastal areas, particularly those with salt fields, was identified as a risk factor for the development of CH.

Up-to-date quality survey and evaluation of neonatal screening programs in China

AIMS

To thoroughly evaluate the quality of the entire process of neonatal screening (NBS) in China.

METHODS

We collected survey questionnaires from 54.4% (135/248) of NBS institutions in China and conducted on-site visits to 20 of these facilities to validate the data. The quality performance of the institutions was evaluated, and differences across various factors were analysed.

RESULTS

Merely 62.5% of the provinces had acceptable performance in neonatal screening. Institutions with limited staff were more prone to organizational management shortcomings. Institutions in provinces with a per capita GDP below 10,000 USD exhibited lower quality control levels than those with a per capita GDP between 10,000 and 15,000 USD. Obstetrics departments have a lower awareness of quality control compared to other blood collection facilities.

CONCLUSIONS

A nationwide, comprehensive quality control system for continuous enhancements in quality management, screening, diagnosis, and treatment is imperative to ensure prompt diagnosis and intervention.

[Newborn blood spot screening (NBS) in Germany : Status quo and presentation of a concept for further development]

Newborn screening from dried blood spots (NBS) is a highly effective secondary prevention measure that has been established for many years. Against the background of the inclusion of "new diseases" that meet the screening criteria, a concept for the further advancement of NBS was developed on behalf of the GKV-Spitzenverband. This was based on a systematic literature review and a survey of the status quo of NBS in Germany using quantitative and qualitative methods.It is essential for the success of NBS that all newborns affected by a target disease are diagnosed and treated at an early stage and that the harm to be expected with each screening (e.g., due to false positive findings) is kept as low as possible. This requires the organisation of screening in the sense of an integrated programme through central coordination with standardised structures, continuous quality management and digitalisation in line with data protection requirements.Although in general NBS is being implemented successfully in Germany, the research project presented here also reveals weaknesses and a need for action. Proposals and recommendations were compiled in a concept paper, which shows approaches for further development of NBS in line with the current state of research in consideration of changing demands on the infrastructure and processes in the health system. This review article summarises the challenges, current status and possible solutions for the central topics of the concept paper.

Free carnitine concentrations and biochemical parameters in medium-chain acyl-CoA dehydrogenase deficiency: Genotype-phenotype correlation

Biallelic variants in the ACADM gene cause medium-chain acyl-CoA dehydrogenase deficiency (MCADD). This study reports on differences in the occurrence of secondary free carnitine (C0) deficiency and different biochemical phenotypes related to genotype and age in 109 MCADD patients followed-up at a single tertiary care center during 22 years. C0 deficiency occurred earlier and more frequently in c.985A>G homozygotes (genotype A) compared to c.985A>G compound heterozygotes (genotype B) and individuals carrying variants other than c.985A>G and c.199C>T (genotype D) (median age 4.2 vs. 6.6 years; p < 0.001). No patient carrying c.199C>T (genotype C) developed C0 deficiency. A daily dosage of 20-40 mg/kg carnitine was sufficient to maintain normal C0 concentrations. Compared to genotype A as reference group, octanoylcarnitine (C8) was significantly lower in genotypes B and C, whereas C0 was significantly higher by 8.28 μmol/L in genotype C (p < 0.05). In conclusion, C0 deficiency is mainly found in patients with pathogenic genotypes associated with high concentrations of presumably toxic acylcarnitines, while individuals carrying the variant c.199C>T are spared and show consistently mild biochemical phenotypes into adulthood. Low-dose carnitine supplementation maintains normal C0 concentrations. However, future studies need to evaluate clinical benefits on acute and chronic manifestations of MCADD.

Target Diseases for Neonatal Screening in Germany

BACKGROUND

Neonatal screening in Germany currently comprises 19 congenital diseases, 13 of which are metabolic diseases. Approximately one in 1300 newborns suffers from one of these target diseases. Early diagnosis and treatment enable the affected children to undergo better development and even, in many cases, to have a normal life.

METHODS

This review is based on pertinent publications retrieved by a selective search in the PubMed and Embase databases.

RESULTS

Positive screening findings are confirmed in approximately one out of five newborns. The prompt evaluation of suspected diagnoses is essential, as treatment for some of these diseases must be initiated immediately after birth to prevent longterm sequelae. The most commonly identified diseases are primary hypothyroidism (1:3338), phenylketonuria/hyperphenylalaninemia (1 : 5262), cystic fibrosis (1 : 5400), and medium-chain acyl-CoA dehydrogenase deficiency (1 : 10 086). Patient numbers are rising as new variants of the target diseases are being identified, and treatments must be adapted to their heterogeneous manifestations. Precise diagnosis and the planning of treatment, which is generally lifelong, are best carried out in a specialized center.

CONCLUSION

Improved diagnosis and treatment now prolong the lives of many patients with congenital diseases. The provision of appropriate long-term treatment extending into adulthood will be a central structural task for screening medicine in the future.

From newborn screening to genomic medicine: challenges and suggestions on how to incorporate genomic newborn screening in public health programs

Newborn screening (NBS) programs are considered among the most effective and efficient measures of secondary prevention in medicine. In individuals with medical conditions, genomic sequencing has become available in routine healthcare, and results from exome or genome sequencing may help to guide treatment decisions. Genomic sequencing in healthy or asymptomatic newborns (gNBS) is feasible and reveals clinically relevant disorders that are not detectable by biochemical analyses alone. However, the implementation of genomic sequencing in population-based screening programs comes with technological, clinical, ethical, and psychological issues, as well as economic and legal topics. Here, we address and discuss the most important questions to be considered when implementing gNBS, such as "which categories of results should be reported" or "which is the best time to return results". We also offer ideas on how to balance expected benefits against possible harms to children and their families.

Twenty years of newborn screening for congenital adrenal hyperplasia and congenital primary hypothyroidism - experiences from the DGKED/AQUAPE study group for quality improvement in Germany

Congenital primary hypothyroidism (CH) and congenital adrenal hyperplasia (CAH) are targeted by the German and Austrian newborn screening. For both diseases, there are registries for quality improvement, based on standardized observational data from long-term patient follow-up, under the auspices of the DGKED study group. By September 2021, the CH registry HypoDOK includes datasets from 23,348 visits of 1,840 patients, and the CAH registry contains datasets from 36,237 visits of 1,976 patients. Here, we report on the recruitment process, patient characteristics, and research contributions from the registries, and underline that the registries are an important tool to improve patient care and outcomes. Registries for rare conditions should thus be considered as an important public health measure and they should be adequately institutionalized and funded.

Newborn Screening: Review of its Impact for Cystinosis

Newborn screening (NBS) programmes are considered to be one of the most successful secondary prevention measures in childhood to prevent or reduce morbidity and/or mortality via early disease identification and subsequent initiation of therapy. However, while many rare diseases can now be detected at an early stage using appropriate diagnostics, the introduction of a new target disease requires a detailed analysis of the entire screening process, including a robust scientific background, analytics, information technology, and logistics. In addition, ethics, financing, and the required medical measures need to be considered to allow the benefits of screening to be evaluated at a higher level than its potential harm. Infantile nephropathic cystinosis (INC) is a very rare lysosomal metabolic disorder. With the introduction of cysteamine therapy in the early 1980s and the possibility of renal replacement therapy in infancy, patients with cystinosis can now reach adulthood. Early diagnosis of cystinosis remains important as this enables initiation of cysteamine at the earliest opportunity to support renal and patient survival. Using molecular technologies, the feasibility of screening for cystinosis has been demonstrated in a pilot project. This review aims to provide insight into NBS and discuss its importance for nephropathic cystinosis using molecular technologies.

The Follow-Up of Chinese Patients in cblC Type Methylmalonic Acidemia Identified Through Expanded Newborn Screening

Objective: The cblC type of combined methylmalonic acidemia and homocystinuria, an inherited disorder with variable phenotypes, is included in newborn screening (NBS) programs at multiple newborn screening centers in China. The present study aimed to investigate the long-term clinical benefits of screening individual.

Methods: A national, retrospective multi-center study of infants with confirmed cblC defect identified by NBS between 2004 and 2020 was conducted. We collected a large cohort of 538 patients and investigated their clinical data in detail, including disease onset, biochemical metabolites, and gene variation, and explored different factors on the prognosis.

Results: The long-term outcomes of all patients were evaluated, representing 44.6% for poor outcomes. In our comparison of patients with already occurring clinical signs before treatment to asymptomatic ones, the incidence of intellectual impairment, movement disorders, ocular complications, hydrocephalus, and death were significantly different (p < 0.01). The presence of disease onset [Odd ratio (OR) 12.39, 95% CI 5.15–29.81; p = 0.000], variants of c.609G>A (OR 2.55, 95% CI 1.49–4.35; p = 0.001), and c.567dupT (OR 2.28, 95% CI 1.03–5.05; p = 0.042) were independently associated with poor outcomes, especially for neurodevelopmental deterioration.

Conclusion: NBS, avoiding major disease-related events and allowing an earlier treatment initiation, appeared to have protective effects on the prognosis of infants with cblC defect.

Actualities in neonatal endocrine and metabolic screening

Neonatal metabolic screening has proven to be an important tool for the early detection of innate metabolic errors. Despite the fact that simple and effective methods of testing for metabolic diseases have been identified since the middle of the twentieth century, no consensus has been reached so far on the content of neonatal metabolic screening panels. There are large differences between countries in the number of metabolic diseases identified through national metabolic screening programs, ranging from zero to several tens, the most common testing being for phenylketonuria and congenital hypothyroidism (including in Romania). Given the fact that rare but treatable diseases have been identified in recent decades, reducing the financial burden on the health system, it would be useful to include them in the national neonatal metabolic screening program.