A relationship between fragile sites, specific genomic regions visible as gaps or breaks on cultivated chromosomes, and human disease has been proposed many years ago. Evidence for a role of the ubiquitously expressed common fragile sites characterized by peculiar genome architecture in cancer has been accumulated over the last years. In contrast, a relationship between the second main group of...

To date over 150 X linked mental retardation (XLMR) conditions have been documented. We describe a five generation South African family with XLMR, comprising 16 affected males and 10 carrier females. The clinical features common to the 16 males included profound mental retardation (100%), mutism despite apparently normal hearing (100%), grand mal epilepsy (87.5%), and limited life expectancy (6...

A genetic study of children attending ESN(M) schools in Coventry has shown a recurrence risk of idiopathic mental retardation in sibs lying between 1 in 4 and 1 in 5. There was also a prevalence of mental retardation in other relatives that was greater than the population prevalence, and was less for second degree relatives than for first degree, and less still for third degree relatives. Recur...

L1 CAM (L1 cell adhesion molecule) plays a key role in the development of nervous system. Recent studies have shown the evidence for the involvement of L1 (CAM) mutations in X-linked mental retardation syndromes. No such studies were undertaken from India and hence, an attempt was made to detect L1 (CAM) mutations in mental retardation. Eight patients from different families were selected to kn...

A syndrome with distinctive facies, poor muscle tone, absent deep tendon reflexes, tapered fingers, excessive fingerprint arches, genu valgum and mild-moderate mental retardation has occurred in four males in two generations of a white family of European ancestry. The facies are characterised by square configuration, tented upper lip, and thickening of the helices, upper eyelids, and alae nasi....

objective mental retardation (mr) or intellectual disability is one of three chronic and disabling neurological disorders of children and adolescents. its prevalence is estimated 1-3% of the population. mr is defined as significant sub-average intellectual functioning and adaptive behavior that become detectable before the age of 18. mr may come into view before 5 years as delay in at least two...

Mutations in either the Rho GTPase pathway or in the fragile X mental retardation (FMR1) gene produce neuronal connectivity defects. In this issue of Neuron, Schenck et al. use biochemical and genetic approaches in Drosophila to examine the interactions between dFMR1 and dRac1 and provide evidence that the cytoplasmic FMRP interacting protein (CYFIP) links Rac-dependent cytoskeleton remodeling ...

Coffin-Lowry syndrome (CLS) is an X-linked disorder, which affects hemizygous males more severely than females. It is characterized by mental retardation, short stature, head and facial abnormalities, skeletal anomalies and developmental delays. The signs and symptoms vary in different people. We report a 14-year-old male patient, diagnosed with CLS based on his clinical features. Genetic testi...

Deficits in cognitive functions lead to mental retardation (MR). Understanding the genetic basis of inherited MR has provided insights into the pathogenesis of MR. Fragile X syndrome is one of the most common forms of inherited MR, caused by the loss of functional Fragile X Mental Retardation Protein (FMRP). MicroRNAs (miRNAs) are endogenous, single-stranded RNAs between 18 and 25 nucleotides i...