Diagnostic yield of various genetic approaches in patients with unexplained developmental delay or mental retardation

  title={Diagnostic yield of various genetic approaches in patients with unexplained developmental delay or mental retardation},
  author={Anita Rauch and Juliane Hoyer and Sabine Guth and Christiane Zweier and Cornelia Kraus and Christian F. W. Becker and Martin Zenker and Ulrike H{\"u}ffmeier and Christian T. Thiel and Franz R{\"u}schendorf and Peter J. N{\"u}rnberg and Andr{\'e} Reis and Udo Trautmann},
  journal={American Journal of Medical Genetics Part A},
The underlying cause of mental retardation remains unknown in up to 80% of patients. As chromosomal aberrations are the most common known cause of mental retardation, several new methods based on FISH, PCR, and array techniques have been developed over recent years to increase detection rate of subtle aneusomies initially of the gene rich subtelomeric regions, but nowadays also genome wide. As the reported detection rates vary widely between different reports and in order to compare the… 

[Diagnostic investigations for an unexplained developmental disability].

Importance of patient selection criteria in determining diagnostic copy number variations in patients with multiple congenital anomaly/mental retardation

The purpose of this study was to determine the copy number variations as well as to investigate methods to increase diagnostic yield of array comparative genomic hybridization and forming a suitable flow chart decision pipeline for test indication especially for developing countries.

Routine Chromosomal Microarray Analysis is Necessary in Korean Patients With Unexplained Developmental Delay/Mental Retardation/Autism Spectrum Disorder

The findings suggest the necessity of CMA as a routine diagnostic test for unexplained DD, MR, and ASD in Korea.

Clinical Utility of Array CGH for the Detection of Chromosomal Imbalances Associated with Mental Retardation and Multiple Congenital Anomalies

Although array CGH is currently being used as an adjunct test to standard karyotype analysis, it is likely to become the genetic test of choice, especially in cases of idiopathic MR/MCA.

Genomic characterization of some Iranian children with idiopathic mental retardation using array comparative genomic hybridization

The array CGH technique increased the detection rate of genomic imbalances in patients with IMR and dysmorphism by 12.5%.

The clinical utility of molecular karyotyping using high-resolution array-comparative genomic hybridization

Clinical characteristics of patients are not always related to specific syndromes. Array-comparative genomic hybridization (aCGH) is used to detect submicroscopic copy number variants within the

Performance of chromosomal microarray for patients with intellectual disabilities/developmental delay, autism, and multiple congenital anomalies in a Chinese cohort

This study provided further evidence of an increased diagnostic yield of CMA and supported its use as a first line diagnostic tool for Chinese individuals with DD/ID, ASD, and MCA.

Cytogenetic Findings in Patients With Intellectual Disability/Mental Retardation and Dysmorphic Features in Eastern Croatia 1

The results of cytogenetic findings in 340 patients with ID/MR and dysmorphia and/or multiple malformations in Eastern Croatia, examined at the Paediatric Clinic of the Clinical Hospital Centre Osijek and the Medical Genetics Laboratory, are shown.

[Genetic screening to determine an etiologic diagnosis in children with mental retardation].

Screening for inborn errors of metabolism in children with intellectual disability should be done always to establish an etiological diagnosis.



Genetic causes of mental retardation

An increasing number of genes causing X-linked mental retardation (XLMR) have been localized and cloned, namely, 38 genes of the 136 known syndromic conditions and 19 for the nonsyndromic condition.

Diagnostic yield of the comprehensive assessment of developmental delay/mental retardation in an institute of child neuropsychiatry.

A retrospective analysis of the diagnostic yield of 120 consecutive patients observed at the Stella Maris Institute, confirming the diagnostic utility of cytogenetic/molecular genetic, and neuroimaging studies and suggesting the usefulness of accurate electroencephalogram recordings, suggests the importance of a thorough physical examination.

Diagnostic investigations in individuals with mental retardation: a systematic literature review of their usefulness

The data from this review allow conclusions for most types of diagnostic investigations in MR patients, and whether the yield differs depending on setting, MR severity, and gender is evaluated.

Detection of chromosomal imbalances in children with idiopathic mental retardation by array based comparative genomic hybridisation (array-CGH)

Array-CGH has become an important tool for the detection of chromosome aberrations and has the potential to identify genes involved in developmental delay and dysmorphism and will increase knowledge of the human genome by performing genotype-phenotype correlation.

Subtelomeric deletions detected in patients with idiopathic mental retardation using multiplex ligation‐dependent probe amplification (MLPA)

This study demonstrates that multiplex ligation‐dependent probe amplification is a fast and reliable screening method, potentially suitable for use in routine diagnostics.

The use of telomere probes to investigate submicroscopic rearrangements associated with mental retardation.

Array-CGH detection of micro rearrangements in mentally retarded individuals: clinical significance of imbalances present both in affected children and normal parents

The limited ability to differentiate between inherited copy number variations which cause abnormal phenotypes and rare variants unrelated to clinical alterations currently constitutes a limitation in the use of CGH-microarray for guiding genetic counselling.

Subtelomere FISH in 50 children with mental retardation and minor anomalies, identified by a checklist, detects 10 rearrangements including a de novo balanced translocation of chromosomes 17p13.3 and 20q13.33

A subtelomere FISH study of 50 unrelated children ascertained by a checklist that evaluates MR or developmental delay, dysmorphism, growth defect, and abnormal pedigree found 10 bona fide causal rearrangements, suggesting that the checklist approach could be especially useful within this group of patients.

Screening for subtelomeric rearrangements in 210 patients with unexplained mental retardation using multiplex ligation dependent probe amplification (MLPA)

Subtelomeric screening can be offered to all mentally retarded patients, although clinical preselection increases the percentage of chromosomal aberrations detected.

Subtelomere specific microarray based comparative genomic hybridisation: a rapid detection system for cryptic rearrangements in idiopathic mental retardation

Mental retardation (MR) occurs in 2–3% of the general population, and more than half of MR patients are categorised as idiopathic—that is, the cause is unknown.1,2 Patients with idiopathic MR are