Assessing the quality and value of metabolic chart data for capturing core outcomes for pediatric medium-chain acyl-CoA dehydrogenase (MCAD) deficiency

BACKGROUND

Generating rigorous evidence to inform care for rare diseases requires reliable, sustainable, and longitudinal measurement of priority outcomes. Having developed a core outcome set for pediatric medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, we aimed to assess the feasibility of prospective measurement of these core outcomes during routine metabolic clinic visits.

METHODS

We used existing cohort data abstracted from charts of 124 children diagnosed with MCAD deficiency who participated in a Canadian study which collected data from birth to a maximum of 11 years of age to investigate the frequency of clinic visits and quality of metabolic chart data for selected outcomes. We recorded all opportunities to collect outcomes from the medical chart as a function of visit rate to the metabolic clinic, by treatment centre and by child age. We applied a data quality framework to evaluate data based on completeness, conformance, and plausibility for four core MCAD outcomes: emergency department use, fasting time, metabolic decompensation, and death.

RESULTS

The frequency of metabolic clinic visits decreased with increasing age, from a rate of 2.8 visits per child per year (95% confidence interval, 2.3-3.3) among infants 2 to 6 months, to 1.0 visit per child per year (95% confidence interval, 0.9-1.2) among those ≥ 5 years of age. Rates of emergency department visits followed anticipated trends by child age. Supplemental findings suggested that some emergency visits occur outside of the metabolic care treatment centre but are not captured. Recommended fasting times were updated relatively infrequently in patients' metabolic charts. Episodes of metabolic decompensation were identifiable but required an operational definition based on acute manifestations most commonly recorded in the metabolic chart. Deaths occurred rarely in these patients and quality of mortality data was not evaluated.

CONCLUSIONS

Opportunities to record core outcomes at the metabolic clinic occur at least annually for children with MCAD deficiency. Methods to comprehensively capture emergency care received at outside institutions are needed. To reduce substantial heterogeneous recording of core outcome across treatment centres, improved documentation standards are required for recording of recommended fasting times and a consensus definition for metabolic decompensations needs to be developed and implemented.

Evaluation of the quality of clinical data collection for a pan-Canadian cohort of children affected by inherited metabolic diseases: lessons learned from the Canadian Inherited Metabolic Diseases Research Network

BACKGROUND

The Canadian Inherited Metabolic Diseases Research Network (CIMDRN) is a pan-Canadian practice-based research network of 14 Hereditary Metabolic Disease Treatment Centres and over 50 investigators. CIMDRN aims to develop evidence to improve health outcomes for children with inherited metabolic diseases (IMD). We describe the development of our clinical data collection platform, discuss our data quality management plan, and present the findings to date from our data quality assessment, highlighting key lessons that can serve as a resource for future clinical research initiatives relating to rare diseases.

METHODS

At participating centres, children born from 2006 to 2015 who were diagnosed with one of 31 targeted IMD were eligible to participate in CIMDRN's clinical research stream. For all participants, we collected a minimum data set that includes information about demographics and diagnosis. For children with five prioritized IMD, we collected longitudinal data including interventions, clinical outcomes, and indicators of disease management. The data quality management plan included: design of user-friendly and intuitive clinical data collection forms; validation measures at point of data entry, designed to minimize data entry errors; regular communications with each CIMDRN site; and routine review of aggregate data.

RESULTS

As of June 2019, CIMDRN has enrolled 798 participants of whom 764 (96%) have complete minimum data set information. Results from our data quality assessment revealed that potential data quality issues were related to interpretation of definitions of some variables, participants who transferred care across institutions, and the organization of information within the patient charts (e.g., neuropsychological test results). Little information was missing regarding disease ascertainment and diagnosis (e.g., ascertainment method - 0% missing).

DISCUSSION

Using several data quality management strategies, we have established a comprehensive clinical database that provides information about care and outcomes for Canadian children affected by IMD. We describe quality issues and lessons for consideration in future clinical research initiatives for rare diseases, including accurately accommodating different clinic workflows and balancing comprehensiveness of data collection with available resources. Integrating data collection within clinical care, leveraging electronic medical records, and implementing core outcome sets will be essential for achieving sustainability.

Development of a clinical assay for detection of GAA mutations and characterization of the GAA mutation spectrum in a Canadian cohort of individuals with glycogen storage disease, type II

Glycogen storage disease, type II (GSDII; Pompe disease; acid maltase deficiency) is an autosomal recessive disease caused by mutations of the GAA gene that lead to deficient acid alpha-glucosidase enzyme activity and accumulation of lysosomal glycogen. Although measurement of acid alpha-glucosidase enzyme activity in fibroblasts remains the gold standard for the diagnosis of GSDII, analysis of the GAA gene allows confirmation of clinical or biochemical diagnoses and permits predictive and prenatal testing of individuals at risk of developing GSDII. We have developed a clinical molecular test for the detection of GAA mutations based on cycle sequencing of the complete coding region. GAA exons 2-20 are amplified in six independent PCR using intronic primers. The resulting products were purified and sequenced. Preliminary studies using this protocol were conducted with DNA from 21 GSDII-affected individuals from five centers across Canada. In total, 41 of 42 mutations were detected (96.7% detection rate). Mutations spanned intron 1 through exon 19 and included nine novel mutations. Haplotype analysis of recurrent mutations further suggested that three of these mutations are likely to have occurred independently at least twice. Additionally, we report the identification of the c.-32-13T>G GAA mutation in an individual with infantile variant GSDII, despite reports of this mutation being associated almost exclusively with late-onset forms of the disease. The development of a clinical molecular test provides an important tool for the management and counseling of families and individuals with GSDII, and has provided useful information about the GAA mutation spectrum in Canada.

Subcutaneous fat necrosis of the newborn and lactic acidosis

Subcutaneous fat necrosis of the newborn (SFN) is an uncommon, self-limited condition of neonates and infants. However, hypercalcemia may be a potentially life-threatening complication of the otherwise self-healing process. Rare complications such as thrombocytopenia, hypertriglyceridemia, hypoglycemia, calcium deposits in the liver, inferior vena cava, atrial septum of the heart, and nephrocalcinosis have been reported. To our knowledge, this is the first description of a patient in whom lactic acidosis was encountered in an infant along with the other known complications of SFN.

Autosomal dominant inheritance of spondyloenchondrodysplasia

Spondyloenchondrodysplasia comprises generalized enchondromatosis with platyspondyly and is thought to be inherited as an autosomal recessive condition. A mother and son are reported with typical features of spondyloenchondrodysplasia. Their similar radiographic and MRI findings are presented. The radiologic appearance of the spine changed over time, illustrating the evolving phenotype of this condition. Transmission from mother to son suggests that dominant pattern of inheritance is possible. A classification of the enchondromatoses is discussed.

Influenza B acute necrotizing encephalopathy: a case report and literature review

The case of a 9-year-old girl with acute encephalopathy with evidence of influenza B virus infection and bilateral basal ganglia lesions is reported. The literature on acute necrotizing encephalopathy is reviewed, and other causes of bilateral basal ganglia lesions are discussed.

Reversible posterior leukoencephalopathy syndrome in a child with cerebral X-linked adrenoleukodystrophy treated with cyclosporine after bone marrow transplantation

Reversible posterior leukoencephalopathy syndrome (RPLS) was described by Hinchey and colleagues in 1996. The disorder occurs predominantly in patients with acute hypertension and/or on pharmacological immunosuppression. We report a 6-year-old male with cerebral X-linked adrenoleukodystrophy who received an HLA-matched unrelated bone marrow transplant (BMT). Cyclosporine was used as graft-versus-host disease prophylaxis. At 55 days post-BMT, his cyclosporine concentrations were high for several days and the concentration was still high on day 70 (353 microg/L). He presented 83 days post-BMT with new onset of headache, lethargy, acute visual loss and focal seizures. He was not hypertensive. MRI of the head revealed signal changes that now extended more peripherally into the subcortical and cortical regions of the occipital and temporal lobes. The patient's cyclosporine was stopped for 5 days. The patient's vision returned to normal and his headaches and lethargy resolved with no further seizures 3 weeks later. Follow-up MRI of the head 2 months later showed almost complete resolution of the cortical signal abnormalities. It is important to consider RPLS in patients with cerebral adrenoleukodystrophy who present with acute neurological deterioration. Attention to the pattern of white matter and the presence of cortical grey matter involvement on neuroimaging is important for the diagnosis. When appropriate management is initiated, that is controlling hypertension when present and discontinuing or reducing the dose of offending immunosuppressive agents, the acute neurological symptoms will usually resolve.