JSCORS: Assessment of the Prevalence of Genes AHI1, NPHP1 and CEP290 in Joubert Syndrome

Sponsor

Assistance Publique - Hôpitaux de Paris (Other)

Overall Status

Completed

CT.gov ID

NCT00873678

Collaborator

(none)

Enrollment

Location

34.1

Duration (Months)

2.3

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Primary objective:

assessment of the prevalence of AHI1 mutations in Joubert syndrome and cerebello-oculo-renal syndromes (JS/CORS)

Secondary objective:

assessment of the prevalence of CEP290 mutations and NPHP1 homozygous deletions in JS/CORS
caracterization of mutational spectrum of AHI1, NPHP1, CEP290 genes in JS/CORS.
evaluation of genotype-phenotype correlation in JS/CORS.

Condition or Disease	Intervention/Treatment	Phase
Joubert Syndrome Cerebello-oculo-renal Syndromes	Biological: Whole blood sample

Detailed Description

Design: multicentric Aims of this study: to describe clinical and genetic basis of Joubert syndrome and cerebello-oculo-renal syndromes.Joubert syndrome (JS) is characterized by hypotonia, abnormal ocular movements and neonatal breathing dysregulation evolving into developmental delay, ataxia, oculomotor apraxia with variable mental retardation. The neuroradiological hallmark of JS is a complex midbrain-hindbrain malformation consisting of vermis hypoplasia/dysplasia, a deepened interpeduncular fossa, and thickened, elongated and mal-orientated superior cerebellar peduncles (Molar Tooth Sign, MTS). Other organs could be involved in JS (kidneys :nephronophthisis or cystic dysplastic kidneys; eyes : Leber Congenital Amaurosis, retinopathy, colobomas); liver : hepatic fibrosis; others: polydactyly, tongue hamartomas, situs inversus). Several associated central nervous system malformations were described : polymicrogyria, hydrocephalus, corpus callosum anomalies and encephalocele. This pleiotropic involvement identifies a large spectrum of cerebello-oculo-renal syndromes or JS Related Disorders (JSRD).

Joubert syndrome and cerebello-oculo-renal syndromes (JS/CORS) are autosomal recessive conditions associated with a high risk of recurrence for further pregnancies (25%). In 2004 mutations in AHI1 gene (Abelson helper integration site gene) were identified in 7-11% JS but the disease is caracterized by a wide genetic heterogeneity. At least five others genes are involved in JS/CORS : NPHP1, which homozygous deletions are responsible for a small percentage of JS (2%) and more recently CEP290 gene which exact mutations prevalence remained to be evaluated.

Using molecular analysis of those three genes (sequencing of 29 coding exons of AHI1 and 54 exons of CEP290, searching for NPHP1 homozygous deletions by PCR analysis) we project to study respective prevalence of mutations of those three genes and described associated phenotypes in 65 JSCORS patients. This work will allowed to described genotype-phenotypes correlation in JSCORS and to progress in the characterization of the underlying pathogenetic mechanisms. It will be the first step before identification of novel disease genes.

Study Design

Study Type:

Observational

Actual Enrollment :

80 participants

Observational Model:

Family-Based

Time Perspective:

Cross-Sectional

Official Title:

Assessment of the Prevalence and Mutational Spectrum of Genes AHI1, NPHP1 and CEP290 in Joubert Syndrome and Cerebello-oculo-renal Syndromes

Study Start Date :

Mar 1, 2007

Actual Primary Completion Date :

Jan 1, 2010

Actual Study Completion Date :

Jan 1, 2010

Arms and Interventions

Arm	Intervention/Treatment
1 Children or adult patients affected with JS/CORS	Biological: Whole blood sample Whole blood sample (10 ml)

Arm

Intervention/Treatment

Children or adult patients affected with JS/CORS

Biological: Whole blood sample

Whole blood sample (10 ml)

Outcome Measures

Primary Outcome Measures

Assessment of the prevalence of AHI1 mutations in Joubert syndrome and cerebello-oculo-renal syndromes (JS/CORS) [At the inclusion visit]

Secondary Outcome Measures

Assessment of the prevalence of CEP290 mutations and NPHP1 homozygous deletions in JS/CORS ; Caracterization of mutational spectrum of AHI1, NPHP1, CEP290 genes in JS/CORS ; Evaluation of genotype-phenotype correlation in JS/CORS. [At the inclusion visit]

Eligibility Criteria

Criteria

Ages Eligible for Study:

N/A and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Child or adult patients without age maximum
Affected with JS/CORS défined by neurologic disease with at least one of the following symptoms :
neonatal hypotonia or developmental delay (before age 3) or mental retardation (QD<70) (after age 3).
Ataxia
Oculomotor apraxia
and on MRI :
vermis hypoplasia/agenesia defined by insufficient development of cerebellar vermis.
And molar tooth defined by thickened, elongated and mal-orientated superior cerebellar peduncles on axial sections.