The Success of a Screening Program Is Largely Dependent on Close Collaboration between the Laboratory and the Clinical Follow-Up of the Patients

Current Status of Newborn Bloodspot Screening Worldwide 2024: A Comprehensive Review of Recent Activities (2020-2023)

Newborn bloodspot screening (NBS) began in the early 1960s based on the work of Dr. Robert "Bob" Guthrie in Buffalo, NY, USA. His development of a screening test for phenylketonuria on blood absorbed onto a special filter paper and transported to a remote testing laboratory began it all. Expansion of NBS to large numbers of asymptomatic congenital conditions flourishes in many settings while it has not yet been realized in others. The need for NBS as an efficient and effective public health prevention strategy that contributes to lowered morbidity and mortality wherever it is sustained is well known in the medical field but not necessarily by political policy makers. Acknowledging the value of national NBS reports published in 2007, the authors collaborated to create a worldwide NBS update in 2015. In a continuing attempt to review the progress of NBS globally, and to move towards a more harmonized and equitable screening system, we have updated our 2015 report with information available at the beginning of 2024. Reports on sub-Saharan Africa and the Caribbean, missing in 2015, have been included. Tables popular in the previous report have been updated with an eye towards harmonized comparisons. To emphasize areas needing attention globally, we have used regional tables containing similar listings of conditions screened, numbers of screening laboratories, and time at which specimen collection is recommended. Discussions are limited to bloodspot screening.

Is Our Newborn Screening Working Well? A Literature Review of Quality Requirements for Newborn Blood Spot Screening (NBS) Infrastructure and Procedures

Newborn screening using dried blood spots (NBS) is widely acknowledged as a highly successful procedure in secondary prevention. For a number of congenital disorders, severe disability or death are impressively prevented by early detection and early treatment through NBS. However, as with any other screening, NBS can also cause harm, and the principle that "the overall benefits of screening should outweigh the harms" must be considered when introducing and implementing NBS programmes. This publication compiles the results of a systematic literature research on requirements for NBS infrastructure and procedures which was conducted as part of a research project on the quality and shortcomings of the NBS pathway in Germany. The compilation contains the requirements and recommendations for realising the principle of "maximise benefits and minimise harms" in relevant NBS pathway components such as parental education and information, coverage, timeliness, laboratory quality assurance, follow-up of abnormal results, confirmatory diagnostics, documentation, and evaluation. The results reflect the complexity of NBS infrastructure, and thus, they illustrate the importance of considering and implementing NBS as a well-coordinated public health programme with continuous quality management. Special attention should be paid to the perspectives of parents and families. Some NBS issues can substantially benefit from digital instruments or international cooperation. The literature review presented here has contributed to a concept of proposals for the advancement of NBS in Germany, and despite different settings, it may as well be of interest for other countries to achieve the best possible course and outcome of NBS for each child.

Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program

Congenital adrenal hyperplasia (CAH) is a common genetic disorder in endocrinology, especially its milder clinical presentation, often caused by a partial or total deficiency of the 21-hydroxylase enzyme located in the adrenal cortex. CAH is characterized by the overproduction of androgen, along with variable degrees of cortisol and aldosterone deficiency. The age at diagnosis can provide some information about underlying mutations, with those diagnosed at birth/early infancy more likely to have severe enzymatic defects, which may include adrenal insufficiency, sexual development disorders, short stature in adulthood, hirsutism, and a higher risk for metabolic syndrome and infertility. Non-classic CAH, a milder form of CAH, is usually manifested later in life and is a common differential diagnosis of Polycystic Ovary Syndrome and should be actively evaluated during initial studies of clinical or biochemical hyperandrogenism. The main goals of CAH treatment are hormone supplementation for severe cases, controlling adrenal androgen overproduction to minimize long-term side effects, managing fertility and genetic counseling, and optimizing patients' quality of life.

Congenital adrenal hyperplasia

Congenital adrenal hyperplasia is a group of autosomal recessive disorders leading to multiple complex hormonal imbalances caused by various enzyme deficiencies in the adrenal steroidogenic pathway. The most common type of congenital adrenal hyperplasia is due to steroid 21-hydroxylase (21-OHase, henceforth 21OH) deficiency. The rare, classic (severe) form caused by 21OH deficiency is characterised by life-threatening adrenal crises and is the most common cause of atypical genitalia in neonates with 46,XX karyotype. After the introduction of life-saving hormone replacement therapy in the 1950s and neonatal screening programmes in many countries, nowadays neonatal survival rates in patients with congenital adrenal hyperplasia are high. However, disease-related mortality is increased and therapeutic management remains challenging, with multiple long-term complications related to treatment and disease affecting growth and development, metabolic and cardiovascular health, and fertility. Non-classic (mild) forms of congenital adrenal hyperplasia caused by 21OH deficiency are more common than the classic ones; they are detected clinically and primarily identified in female patients with hirsutism or impaired fertility. Novel treatment approaches are emerging with the aim of mimicking physiological circadian cortisol rhythm or to reduce adrenal hyperandrogenism independent of the suppressive effect of glucocorticoids.

Genotype-phenotype association in congenital adrenal hyperplasia due to 21-hydroxylase deficiency in children

OBJECTIVE

The purpose of this study was to investigate the clinical manifestation of various forms of congenital adrenal hyperplasia (CAH) in children of the Republic of Kazakhstan, depending on their genotype.

DESIGN

The study analysed 50 patients diagnosed with CAH from 7 regions of Kazakhstan with different ethnic origins: 35 Kazakhs (70.0%), 8 Russians (16.0%), 2 Turks (4.0%), 2 Ukrainians (4.0%), 2 Uzbeks (4%), 1 Uighur (2%). All the children studied were from 0 to 18 years old, and their average age was 5.7 years ±3.9. In addition, all children were divided into groups depending on the form of the disease according to the phenotypic manifestation of the disease: salt-wasting (SW) and simple virile (SV) forms. Most of the patients suffered from SW - 32 (64.0%), and a smaller group had SV - 18 (36.0%), also one boy with SW was diagnosed with TART syndrome.

MEASUREMENTS

50 Kazakh children with the classical form of CAH were analysed. Depending on the severity of the mutations, patients were divided into 4 groups: zero groups (the most severe mutations), A, B, and C.

RESULTS

According to the results of the study, the salt-wasting form of CAH turned out to be more common than the simple virile form. A high correlation was observed in groups with mutations of high and moderate severity - 0 and A, while group C showed a strong variability of the phenotype. Thus, the correspondence between genotype and phenotype decreased along with the decrease in the severity of the disease.

CONCLUSIONS

The relationship between the genotype and the phenotype of both forms of CAH exists indirectly, through the activity of the 21-hydroxylase enzyme. Mutations in the CYP21A2 gene affect the level of the synthesized enzyme, which, in turn, determines the degree of hormone production in the blood.

How longitudinal observational studies can guide screening strategy for rare diseases

Newborn screening (NBS) is an important secondary prevention program, aiming to shift the paradigm of medicine to the pre-clinical stage of a disease. Starting more than 50 years ago, technical advances, such as tandem mass spectrometry (MS/MS), paved the way to a continuous extension of NBS programs. However, formal evidence of the long-term clinical benefits in large cohorts and cost-effectiveness of extended NBS programs is still scarce. Although published studies confirmed important benefits of NBS programs, it also unraveled a significant number of limitations. These include an incompletely understood natural history and phenotypic diversity of some screened diseases, unreliable early and precise prediction of individual disease severity, uncertainty about case definition, risk stratification, and indication to treat, resulting in a diagnostic and treatment dilemma in individuals with ambiguous screening and confirmatory test results. Interoperable patient registries are multi-purpose tools that could help to close the current knowledge gaps and to inform further optimization of NBS strategy. Standing at the edge of introducing high throughput genetic technologies to NBS programs with the opportunity to massively extend NBS programs and with the risk of aggravating current limitations of NBS programs, it seems overdue to include mandatory long-term follow-up of NBS cohorts into the list of screening principles and to build an international collaborative framework that enables data collection and exchange in a protected environment, integrating the perspectives of patients, families, and the society.

Long-Term Outcomes of Congenital Adrenal Hyperplasia

A plethora of negative long-term outcomes have been associated with congenital adrenal hyperplasia (CAH). The causes are multiple and involve supra-physiological gluco- and mineralocorticoid replacement, excess adrenal androgens both intrauterine and postnatal, elevated steroid precursor and adrenocorticotropic hormone levels, living with a congenital condition as well as the proximity of the cytochrome P450 family 21 subfamily A member 2 (CYP21A2) gene to other genes. This review aims to discuss the different long-term outcomes of CAH.

The impact of adherence and therapy regimens on quality of life in patients with congenital adrenal hyperplasia

OBJECTIVE

Varying outcomes regarding the quality of life (QoL) have been reported in patients with congenital adrenal hyperplasia (CAH). To assess the impact of adherence rate to medical therapy regimens on QoL in patients with CAH.

PATIENTS

Adolescents and adults aged 15-72 years with CAH due to 21-hydroxylase deficiency at Karolinska University Hospital, Stockholm, Sweden.

MEASUREMENTS

QoL was assessed using the Addison QoL (n = 72) and RAND 36 questionnaires (n = 75). Adherence to therapy regimens was measured using the Adherence Starts with Knowledge questionnaire (ASK-12). Associations between QoL, type of glucocorticoid therapy prescribed and ASK-12 results were examined. Results were compared to reference RAND 36 data obtained from a representative sample from the general Swedish population.

RESULTS

A good adherence rate to therapy regimens and a younger age were key factors for a better QoL in study participants with CAH. Younger patients on hydrocortisone and with good adherence had higher RAND 36 scores than older patients on prednisolone independently adherence. Participants with classic CAH (both the salt-wasting and simple virilizing form) reported higher QoL than those with nonclassic CAH. Patients with CAH, especially nonclassic, more frequently reported an impaired QoL than the general population, especially regarding limitations related to body pain, vitality and mental health.

CONCLUSION

A poor adherence rate to therapy regimens, rather than type of glucocorticoid was associated with impaired QoL in adolescents and adults with CAH.

Molecular Diagnosis of Steroid 21-Hydroxylase Deficiency: A Practical Approach

Adrenal insufficiency in paediatric patients is mostly due to congenital adrenal hyperplasia (CAH), a severe monogenic disease caused by steroid 21-hydroxylase deficiency (21-OHD, encoded by the CYP21A2 gene) in 95% of cases. CYP21A2 genotyping requires careful analyses that guaranty gene-specific PCR, accurate definition of pseudogene-gene chimeras, gene duplications and allele dropout avoidance. A small panel of well-established disease-causing alterations enables a high diagnostic yield in confirming/discarding the disorder not only in symptomatic patients but also in those asymptomatic with borderline/positive results of 17-hydroxyprogesterone. Unfortunately, the complexity of this locus makes it today reluctant to high throughput techniques of massive sequencing. The strong relationship existing between the molecular alterations and the degree of enzymatic deficiency has allowed genetic studies to demonstrate its usefulness in predicting/classifying the clinical form of the disease. Other aspects of interest regarding molecular studies include its independence of physiological variations and analytical interferences, its usefulness in the diagnosis of simple virilizing forms in males and its inherent contribution to the genetic counseling, an aspect of great importance taking into account the high carrier frequency of CAH in the general population. Genetic testing of CYP21A2 constitutes an irreplaceable tool to detect severe alleles not just in family members of classical forms but also in mild late-onset forms of the disease and couples. It is also helpful in areas such as assisted reproduction and preimplantation diagnosis. Molecular diagnosis of 21-OHD under expert knowledge definitely contributes to a better management of the disease in every step of the clinical course.

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.

Increased Prevalence of Fractures in Congenital Adrenal Hyperplasia: A Swedish Population-based National Cohort Study

CONTEXT

Low bone mineral density has been reported in individuals with congenital adrenal hyperplasia (CAH), but the prevalence of fractures is unclear.

OBJECTIVE

To study the prevalence of fractures in CAH.

DESIGN, SETTING, AND PARTICIPANTS

Patients with CAH (n = 714, all 21-hydroxylase deficiency) were compared with controls matched for sex and year and place of birth (n = 71 400). Data were derived by linking National Population-Based Registers.

MAIN OUTCOME MEASURES

Number and type of fractures.

RESULTS

Mean age was 29.8 ± 18.4 years. Individuals with CAH had more fractures compared to controls [23.5% vs 16.1%, odds ratio (OR) 1.61, 95% CI 1.35-1.91], and this was found in both sexes (females: 19.6% vs 13.3%, OR 1.57, 95% CI 1.23-2.02; males: 28.7% vs 19.6%, OR 1.65, 95% CI 1.29-2.12). Fractures were significantly increased in patients born before the introduction of neonatal screening but not in those born afterwards. Any major fracture associated with osteoporosis (spine, forearm, hip, or shoulder) was increased in all individuals with CAH (9.8% vs 7.5%, OR 1.34, 95% CI 1.05-1.72). The highest prevalence of fractures was seen in SV phenotype and I172N genotype while nonclassic phenotype and I2 splice genotype did not show increased prevalence. A transport accident as a car occupant and fall on the same level were more common in patients with CAH, both sexes, than in controls.

CONCLUSIONS

Patients with CAH had an increased prevalence of both any fracture and fractures associated with osteoporosis (both sexes) but not for patients neonatally screened. We conclude that fracture risk assessment and glucocorticoid optimization should be performed regularly.

Impact of Newborn Screening on Clinical Presentation of Congenital Adrenal Hyperplasia

Background and Objectives: The main reason for Newborn screening (NBS) for congenital adrenal hyperplasia (CAH) is to prevent adrenal insufficiency that can lead to life-threatening conditions. On the other hand, screening programs are not always sensitive and effective enough to detect the disease. We aimed to evaluate impact of the national NBS on the clinical presentation of patients with CAH in Lithuania. Materials and Methods: A retrospective study was performed on data of 88 patients with CAH from 1989 to 2020. Patients with confirmed CAH were divided into two groups: (1) 75 patients diagnosed before NBS: 52 cases with salt-wasting (SW), 21 with simple virilising (SV) and two with non-classical (NC) form; (2) 13 patients diagnosed with NBS: 12 cases with SW and 1 case with SV form. For the evaluation of NBS effectiveness, data of only male infants with salt-wasting CAH were analysed (n = 36, 25 unscreened and nine screened). Data on gestational age, birth weight, weight, symptoms, and laboratory tests (serum potassium and sodium levels) on the day of diagnosis, were analysed. Results: A total of 158,486 neonates were screened for CAH from 2015 to 2020 in Lithuania and CAH was confirmed in 13 patients (12 SW, one–SV form), no false negative cases were found. The sensitivity and specificity of NBS program for classical CAH forms were 100%; however, positive predictive value was only 4%. There were no significant differences between unscreened and screened male infant groups in terms of age at diagnosis, serum potassium, and serum sodium levels. Significant differences were found in weight at diagnosis between the groups (−1.67 ± 1.12 SDS versus 0.046 ± 1.01 SDS of unscreened and screened patients respectively, p = 0.001). Conclusions: The sensitivity and specificity of NBS for CAH program were 100%, but positive predictive value—only 4%. Weight loss was significantly lower and the weight SDS at diagnosis was significantly higher in the group of screened patients.

Newborn Screening for CAH-Challenges and Opportunities

Newborn screening for congenital adrenal hyperplasia (CAH) using 17-hydroxyprogesterone (17-OHP) as an indicator of disease was first introduced in the 1970s [...].

Neonatal Screening for MPS Disorders in Latin America: A Survey of Pilot Initiatives

Newborn screening enables the diagnosis of treatable disorders at the early stages, and because of its countless benefits, conditions have been continuously added to screening panels, allowing early intervention, aiming for the prevention of irreversible manifestations and even premature death. Mucopolysaccharidoses (MPS) are lysosomal storage disorders than can benefit from an early diagnosis, and thus are being recommended for newborn screening. They are multisystemic progressive disorders, with treatment options already available for several MPS types. MPS I was the first MPS disorder enrolled in the newborn screening (NBS) panel in the USA and a few other countries, and other MPS types are expected to be added. Very few studies about NBS for MPS in Latin America have been published so far. In this review, we report the results of pilot studies performed in Mexico and Brazil using different methodologies: tandem mass spectrometry, molecular analysis, digital microfluidics, and fluorimetry. These experiences are important to report and discuss, as we expect to have several MPS types added to NBS panels shortly. This addition will enable timely diagnosis of MPS, avoiding the long diagnostic odyssey that is part of the current natural history of this group of diseases, and leading to a better outcome for the affected patients.