Breakpoint Analysis of de Novo Apparently Balanced Chromosomal Translocations

NCT01826708 | Completed Early Phase 1 DMC

• 1 other identifier: 8688
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

For every child with developmental delay, the investigators do a constitutional karyotype. This karyotype can reveal an apparently balanced chromosomal rearrangement (no visible loss or gain of genetic material), such as a translocation between two or more chromosomes of accidental occurrence (not transmitted by parents). However, an apparently balanced translocation does not explain the phenotype of the child. Among the hypotheses that could explain the child's symptoms, there is the possibility of another chromosomal abnormality at the translocation breakpoints, another defect elsewhere on the chromosomes or gene disruption at or near the breakpoints. Because the resolution of a constitutional karyotype is limited, these microanomalies can go undiagnosed. The goal of this study is to look for a microanomaly on a chromosome using a technology of higher resolution than that of the conventional karyotype. The proposed study uses DNA microarray technology on DNA extracted from blood lymphocytes to perform high-resolution analysis of all chromosomes to search for an unbalanced microrearrangement (such as loss or gain of chromosomal material). If no microrearrangement is found, the investigators will pursue by looking for a gene disruption defect at or near the breakpoints involved in the translocation. This will be done by first isolating the chromosomes involved in the translocation by flow cytometry and then hybridizing each of the isolated chromosomes on a new microarray. The purpose of this study is to find a possible cause to explain the phenotype (microrearrangement or gene disruption).

Conditions

Balanced Chromosomal Translocation

Keywords

Chromosomal translocations; psychomotor delay

Outcome Measures

Primary Outcomes (1)

• Evaluation of the proportion of cases for which a cause explaining the phenotype is found for patients with a apparently balance de novo translocation

  Evaluation of the proportion of cases for which a cause explaining the phenotype is found for patients with a apparently balance de novo translocation

  6 months and 2 years

Study Arms (1)

Psychomotor retardation syndromic

NO INTERVENTION

Psychomotor retardation syndromic by Identification of breakpoints

Biological: Identification of breakpoints

Interventions

Identification of breakpoints BIOLOGICAL

Identification of breakpoints in Molecular Biology : demonstration of a chimeric sequence corresponding to a junction region between the two chromosomes

Psychomotor retardation syndromic

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• patient with syndromic psychomotor delay
• patient with a apparently balanced de novo chromosomal translocation
• patient with health insurance
• informed consent signed by patient or by parents or by the legal representative for children

You may not qualify if:

• patient with an inherited translocation

Sponsors & Collaborators

• University Hospital, Montpellier: lead

Study Sites (1)

Laboratory of Chromosomal Genetics - Universitary Hospital

Montpellier, 34295, France

Location

Related Publications (2)

• Gribble SM, Prigmore E, Burford DC, Porter KM, Ng BL, Douglas EJ, Fiegler H, Carr P, Kalaitzopoulos D, Clegg S, Sandstrom R, Temple IK, Youings SA, Thomas NS, Dennis NR, Jacobs PA, Crolla JA, Carter NP. The complex nature of constitutional de novo apparently balanced translocations in patients presenting with abnormal phenotypes. J Med Genet. 2005 Jan;42(1):8-16. doi: 10.1136/jmg.2004.024141.

  PMID: 15635069 BACKGROUND

• Yauy K, Schneider A, Ng BL, Gaillard JB, Sati S, Coubes C, Wells C, Tournaire M, Guignard T, Bouret P, Genevieve D, Puechberty J, Pellestor F, Gatinois V. Disruption of chromatin organisation causes MEF2C gene overexpression in intellectual disability: a case report. BMC Med Genomics. 2019 Aug 2;12(1):116. doi: 10.1186/s12920-019-0558-8.

  PMID: 31375103 RESULT

MeSH Terms

Conditions

Translocation, Genetic; Learning Disabilities

Condition Hierarchy (Ancestors)

Chromosome Aberrations; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Communication Disorders; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Neurodevelopmental Disorders; Mental Disorders

Study Officials

• Jacques MD Puechberty, PHD

  Laboratory of Chromosomal Genetics - Universitary Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: early phase 1
• Allocation: NA
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 29, 2012
• First Posted: April 8, 2013
• Study Start: October 1, 2011
• Primary Completion: January 8, 2015
• Study Completion: January 8, 2015
• Last Updated: June 12, 2026

Record last verified: 2026-06

Locations

FR (1)