Ten genes (i.e., ZNF711, SRPX2, RAB40AL, MID2, ACSL4, PAK3, UBE2A, UPF3B, CUL4B, and GRIA3) in the duplication interval have been associated with mental retardation.
Here, using oligoarray-based comparative genomic hybridization (array CGH), we identified a de novo deletion of the CUL4B gene in a boy with syndromic mental retardation, minor facial anomalies, short stature, delayed puberty, hypogonadism, relative macrocephaly, gait ataxia, and pes cavus, all manifestations described previously in patients with CUL4B point mutations.
Autosomal dominant mental retardation-7 (MRD7) is a rare anomaly, characterized by severe intellectual disability, feeding difficulties, behavior abnormalities, and distinctive facial features, including microcephaly, deep-set eyes, large simple ears, and a pointed or bulbous nasal tip.
The two subjects with the mutations in the coding region had family members with mental retardation, which suggests that the novel frame shift mutation and the missense mutation at coding region of ATRX gene are involved in ATRX syndrome.
Mecp2 is a transcriptional repressor protein that is mutated in Rett syndrome, a neurodevelopmental disorder that is the second most common cause of mental retardation in women.
The purpose of this study was to investigate the role of evolutionarily conserved cis-elements in regulating the post-transcriptional expression of the MECP2 gene and to explore their possible correlations with a mutation that is known to cause mental retardation.
Alternatively, testing for large-scale MECP2 duplications is recommended for males presenting with mental retardation, an X-linked family history of developmental delay, and a significant proportion of previously described clinical features (particularly a history of recurrent respiratory infections).
In this study we summarize the results of diagnostic testing of 30 patients with Rett syndrome (RTT) or mental retardation of unknown etiology using bidirectional sequencing of the open reading frame of the MECP2 gene.
The aim of the study was: (a) to evaluate the incidence and spectrum of MECP2 mutations in children with RTT and variant MR; (b) to evaluate phenotype-genotype correlations.
Rett syndrome (RS), an X-linked neurodevelopmental disorder and the common cause of mental retardation in females, is caused by methyl CpG binding protein 2 (MECP2) gene mutations with a frequency of more than 95% in classical Rett patients.
While not genome-wide significant, the gene with the strongest association (p-value = 8.7×10(-5)) was DYRK1A, a gene previously related to abnormal brain development and mental retardation.
Rett syndrome (RTT), a neurodevelopmental disorder caused by mutations in the X-linked gene encoding methyl-CpG-binding protein2 (MeCP2), is a leading cause of mental retardation in females.
The identification of hundreds of genes deregulated by DYRK1A overexpression and numerous cytosolic, cytoskeletal and nuclear proteins, including transcription factors, phosphorylated by DYRK1A, indicates that DYRK1A overexpression is central for the deregulation of multiple pathways in the developing and aging DS brain, with structural and functional alterations including mental retardation and dementia.
This case broadens the phenotypic spectrum of MECP2 abnormalities with consequent implication in diagnosis and genetic counselling of girls with non-syndromic mental retardation.
This study examined the effects of sedation on auditory brainstem response interpeak latency intervals (i.e., I-III, III-V, and I-V) in two groups: (1) a group with Rett syndrome who were positive for mutations in the MECP2 gene and (2) a group negative for mutations in the MECP2 gene but who were severely to profoundly delayed with other causes of mental retardation.
These findings corroborate other recent reports in the literature and highlight that the overexpression of MECP2 caused by duplications involving this gene is a relatively frequent genetic cause of mental retardation in males, highlighting the importance of MECP2 gene dosage for diagnostic purposes in such cases.