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The Cognitive Variability in NF1 and TSC Monozygotic Twins

NCT02436746 · Status: UNKNOWN · Type: OBSERVATIONAL · Enrollment: 116

Last updated 2015-05-07

No results posted yet for this study

Summary

Both Neurofibromatosis type 1 (NF1) and Tuberous Sclerosis Complex (TSC) are highly heterogeneous diseases. Cognitive features seem to vary widely even between family members carrying the same mutation. This phenotypic variability is not well understood, but is generally assumed to be caused by modifier genes which regulate the affected pathways. However, recent studies brought forward an alternative explanation for the phenotypic variability. Post-mortem studies showed that second hit mutations causing loss of the second ('healthy') allele are more widespread than previously believed. These loss of heterozygosity (LOH) mutations cause bi-allelic loss of the disease-linked gene and are known to cause the gross of somatic features in both diseases (like neurofibromas and hamartomas). Hence, it could be the stochastic occurrence of second-hit mutations in the brain are the cause of the variable cognitive phenotypes.

To investigate to what extent these LOH mutations in the brain contribute to the phenotype and to what extent this variation is due to genetic modifiers factors is unknown. The investigators therefore propose to elucidate this variability by comparing the correlation of cognitive features of monozygotic twins with NF1 or TSC to healthy twins in the population. If modifier genes are the cause of the variability of cognitive features in NF1 and TSC the investigators expect that the variability in cognitive tests in monozygotic twins is the same as monozygotic twins in the healthy population. However, if the variability is caused by the occurrence of LOH mutations, the investigators expect to have a lower correlation in our monozygotic patients compared to the healthy twins.

Conditions

  • Neurofibromatosis Type I
  • Tuberous Sclerosis Complex

Sponsors & Collaborators

Principal Investigators

  • Ype Elgersma, Prof. · Erasmus Medical Center

Eligibility

Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2015-04-30
Primary Completion
2017-04-30
Completion
2017-04-30

Countries

  • Netherlands

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT02436746 on ClinicalTrials.gov