Screening of Lysosomal Storage Disorders Diseases in Minority Groups

Enzymatic and Genotypic Screening of Lysosomal Storage Diseases in Minority Groups

Aim is to undertake a screening study that identifies undiagnosed patients with LSDs and determine the prevalence of these diseases with special focus on underrepresented minority groups.

Study Overview

• Status: Unknown
• Conditions: Lysosomal Storage Diseases
• Intervention / Treatment: Diagnostic test: Enzyme assay and molecular sequencing

Detailed Description

Lysosomes are small, cytoplasmic organelles that contain several acid hydrolase enzymes. These enzymes break down foreign materials and cellular debris allowing the lysosomes to act as recycling centers for the cells. Following DNA transcription, lysosomal enzymes are produced in the endoplasmic reticulum and targeted to lysosomes by specific recognition markers. If one of the enzymes is absent or if its function is diminished due to either an altered amino acid sequence of the protein or defective intracellular trafficking, the macromolecules metabolized by the specific enzyme will gradually accumulate in the lysosomes. Abnormal substrate storage leads to cellular dysfunction followed by cell death ultimately manifesting as tissue damage and organ failure.

More than 50 metabolic disorders resulting from defective lysosomal enzyme function have been described and are classified as lysosomal storage disorders (LSDs). Although individually uncommon (less than 1 in 100,000), the combined incidence of this group of genetic disorders is about 1 in 5,000 to 1 in 10,000. The prevalence might be even higher than predicted due to undiagnosed instances or misdiagnosis of milder cases.

Most of LSDs are inherited in an autosomal recessive manner except two disorders: Fabry disease and Hunter syndrome, which are X chromosome linked. Two healthy carriers of the same autosomal recessive disease may have an affected child. Usually the carriers are unaware of their carrier status prior to screening or until they have a sick child. These disorders are more common in communities with high consanguinity and where cousin marriages are allowed. In the case of X-linked diseases, the mutant gene is passed down from one generation to the next one in a specific way. If a male has an abnormal copy of the specific gene, he will show the typical presentation of the disease. If a woman has an abnormal copy of the specific gene, she may develop some milder symptoms of the disease due to random X- inactivation.

Screening for LSDs is performed by measuring enzymatic activity in peripheral blood. The most cost effective and convenient way is to use dried filter paper blood spots. A positive screening result has to be followed by a confirmatory enzymatic testing using white blood cells, plasma or cultured skin fibroblasts and/or DNA mutation analysis. The importance of screening for LSDs has been recognized by several state governments as these tests are being included in many newborn screening programs. Although newborn screening helps to identify patients early on, there is still an unmet need for population screening and for identifying patients with reversible tissue damage. LSDs cause serious and progressive problems with multiple body systems. Therapy is available and is promising in most cases. Importantly, patients with LSDs require thorough management plans for their complex health issues.

• Study Type: Observational
• Enrollment (Anticipated): 100000

Contacts and Locations

Study Locations

• United States
  • Virginia
    • Fairfax, Virginia, United States, 22030
      • LDRTC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

The study population will comprise of patients of healthcare institutions in the Washington, D.C. and Richmond, Virginia areas including but not limited to hospitals, clinics, and doctor's offices.

Description

Inclusion Criteria:

• To be enrolled in this study the subject must meet the following (inclusion) criteria:

  • Subject is greater than or equal to 1 day of age and less than or equal to 100 years of age
  • Subject is managed by a physician in the Washington, D.C and Richmond, VA metro area
  • Subject is getting blood work as part of standard clinical care and there is at least 60 uL blood remained in a tube after all clinical tests were run

Exclusion Criteria:

• subjects must not meet any of the following (exclusion) criteria:

  • Absolute contraindication for blood drawing
  • Subject cannot be traced back by the referring physician upon a positive screening result

Study Plan

How is the study designed?

Design Details

• Observational Models: Ecologic or Community
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Screen population; The study population will comprise of patients of healthcare institutions in the Washington, D.C. metro area including but not limited to hospitals, clinics, and doctor's offices.	Diagnostic test: Enzyme assay and molecular sequencing; Enzyme assay and molecular sequencing on relevant samples conducted from left over blood samples

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Enzyme activity analysis to identify subjects with Lysosomal storage disorders	To identify patients with LSDs using enzymatic activity specific to individual lysosomal storage disorders using left-over blood of blood samples collected as part of standard clinical care.	5 years
Genotypic analysis of subjects with abnormal enzyme activity	Samples from subjects with abnormally low enzyme activity will be used for targeted sequencing analysis to diagnose any pathologic mutations.	5 years

Collaborators and Investigators

• Sponsor: Lysosomal and Rare Disorders Research and Treatment Center, Inc.
• Investigators: Principal Investigator: Margarita M Ivanova, PhD, LDRTC; Principal Investigator: Ozlem Goker-Alpan, MD, LDRTC

Publications and helpful links

Helpful Links

• Institute website for more details

Study record dates

Study Major Dates

• Study Start (Actual): March 17, 2016
• Primary Completion (Anticipated): December 1, 2019
• Study Completion (Anticipated): December 1, 2019

Study Registration Dates

• First Submitted: January 18, 2019
• First Submitted That Met QC Criteria: January 18, 2019
• First Posted (Actual): January 22, 2019

Study Record Updates

• Last Update Posted (Actual): January 22, 2019
• Last Update Submitted That Met QC Criteria: January 18, 2019
• Last Verified: January 1, 2019

More Information

Terms related to this study

• Keywords: Gangliosidoses; Gaucher disease; Fabry disease; Pompe disease
• Additional Relevant MeSH Terms: Metabolic Diseases; Genetic Diseases, Inborn; Metabolism, Inborn Errors; Lysosomal Storage Diseases
• Other Study ID Numbers: 16-LDRTC-04

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No