Study concluded by Stanford University

NGLY1 deficiency is a rare genetic disorder that is characterized by: global developmental delay and/or intellectual disability, hypo- or alacrima, transient elevation of transaminases, and a hyperkinetic movement disorder. Significant phenotypic variability has been observed in the small number of affected individuals described in the medical literature.

The purpose of this study is to describe the natural history of NGLY1 deficiency in a prospective, detailed, and highly uniform manner. Study participants will be closely monitored over the course of five years in order to:

• understand the clinical spectrum and progression of NGLY1 deficiency using standardized clinical and neurodevelopmental assessments
• identify clinical and biomarker endpoints for use in therapeutic trials, and
• identify genotype-phenotype correlations

Close clinical follow-up will allow for generation of a rich dataset and detailed understanding of the natural history of NGLY1 deficiency.

Inclusion Criteria:

• Parent(s)/legal representative and/or participant must be willing and able to give informed consent/assent for participation in the study
• Males or females of any age
• Suspected or confirmed diagnosis of NGLY1 deficiency with genetic variants in both NGLY1 alleles and consistent clinical characteristics
• Participant and caregiver must be willing to provide clinical data, participate in standardized assessments, and provide biological samples (if living in the United States)
• Willingness to travel to Palo Alto, CA is favored, but not required

Exclusion Criteria:

• The presence of a second, confirmed disorder, genetic or otherwise, affecting neurodevelopment or with other overlapping symptoms of NGLY1 deficiency

Individuals of any age with NGLY1 deficiency.

Researchers and clinicians with academic interest in NGLY1 deficiency may be provided access to data obtained through this study. Any data or samples shared outside of Stanford University will be done so in a coded fashion with no protected health information included and with the execution of all applicable agreements (i.e. a material transfer agreement) or ongoing collaborations as approved in eProtocol 47335.