Retrospective Study of Adult Patients With Inborn Errors of Metabolism in Switzerland

Study Overview
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Brief Summary
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This is a retrospective study aimed at establishing a database of the current health of adult patients with IEM in the French-speaking part of Switzerland. .

Detailed Description
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Background Inborn errors of metabolism (IEMs) are a group of rare disorders caused by genetic mutations that affect enzymes of intermediary metabolism. Because adult with IEMs has become an emerging and challenging group in Switzerland, this study is intended to assess the actual situation of adult patients with IEM in the French-speaking part of Switzerland, namely their age, their sex, their diagnosis, age at disease onset and their clinical outcome including complications of the disease. All adult patients with a biochemical and/or genetic diagnosis of IEM followed at the adult metabolic clinic from the Lausanne University Hospital and Geneva University Hospital between 01.10.2013 to 31.12.2017 will be included in the study. In addition, investigators will also include the patients referred to the clinic for suspicion of IEM and determinate if the investigation confirmed an IEM disease. Electronic and paper patient charts will be reviewed for clinical features, biochemical investigations, molecular genetic testing, diagnostic imaging, treatment and long-term outcome. All data will be entered in an Excel database.

Official Title
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Clinical Characteristics of Adult Patients With Inborn Errors of Metabolism in French-speaking Switzerland

Conditions
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Inborn Errors of Metabolism

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All IEM adult patients who were transitioned from the pediatric clinic to the adult metabolic clinic (the Centre for Molecular Disease in Lausanne and the Division of Endocrinology, Diabetology, Hypertension and Nutrition of the HUG) since its creation in 2013 and those who were referred to our clinic for suspicion of IEM and requiring further investigation. Exclusion Criteria: Age < 16 years . Any document attesting a refusal to participate will exclude the data entry of the concerned patient.

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Specific diagnosis of IEM listed by their frequency | Clinical outcome | First visit | 
| Age at diagnosis (years/months) | Clinical outcome | First visit | 
| Medical complications | Clinical outcome including acute liver failure, nephropathy, metabolic acidosis, ophthalmologic anomalies, epilepsy, encephalopathy, myopathy, neuropathy, diabetes | 4 years | 
| Specific treatment for Inborn Errors of Metabolism | Treatment specific to each diseases including ammonia scavenger, enzyme replacement therapy, carnitine, ubiquinone, vitamins, specific diet, dialysis, specific metabolic formula | 4 years | 
| Number of hospital admission | Clinical outcome | 4 years | 
| Survival rate (%) | Clinical Outcome | 4 years | 
| Gender (Male/female) | Demography outcome | First visit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Abdominal Ultrasound results | Radiological Imaging description of spleen and/or liver when available (size, echostructure) | 4 years | 
| Magnetic resonance Imaging scan | Radiological Imaging description of brain, abdomen and bone when available | 4 years | 
| Bone density test | Radiological Imaging description of bone including T-score when available | 4 years | 
| Biological biomarkers of specific diseases (lysosomal storage disorders and galactosemia) | Laboratory including blood concentration of chitotriosidase and Galactose-1-Phosphate | 4 years | 
| Clinical chemistry | Laboratory including blood concentration of sodium, potassium, liver function tests, creatinine, uric acid, urea, amino acids, acylcarnitine profile, methylmalonate, total homocysteine and urine concentration of organic acids | 4 years | 
| Hematology tests | Laboratory (blood count, international normalized ratio, prothrombin time) | 4 years | 
| Enzyme activity in leucocytes and/or fibroblasts | Enzyme activity of deficient enzyme when available for lysosomal storage diseases, mucopolysaccharidoses, cobalamin deficiency, diseases, classical homocystinuria | 4 years | 
| Molecular analysis results of candidate gene for Inborn Errors of metabolism | Laboratory including mutation results confirming the molecular origin of the disease when available | 4 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Inborn errors of Metabolism, Adulthood, Clinical characteristics