5q14.3 deletions including the MEF2C gene have been identified to date using genomic arrays in patients with severe developmental delay or intellectual disability, stereotypic behavior, epilepsy, cerebral malformations and a facial gestalt not really distinctive though characterized by broad and/or high, bulging forehead, upslanting palpebral fissures, flat nasal root and bridge, small, upturned nose, hypotonic small mouth resulting in cupid bow/tented upper lip.
Developmental delay has been reported in males with Xp21 deletion when the deletion extends proximally to include <i>DMD</i> or when larger deletions extend distally to include <i>IL1RAPL1</i> and <i>DMD.</i>
OPA3 mutations (IVS1-1G>C) were identified in 2 patients with the classic phenotype of type III 3MGA, but not in the other 11 patients with differing non-Costeff phenotypes associated with developmental delay and neurological signs and symptoms as described.
CAPS2-deficient (CAPS2(-/-)) mice show reduced secretion of BDNF and NT-3; consequently, the cerebella of these mice exhibit developmental deficits, such as delayed development and increased cell death in GCs, fewer branched dendrites on Purkinje cells (PCs), and loss of the intercrural fissure.
NDN is one of several genes inactivated in Prader-Willi syndrome (PWS), a developmental disorder characterized by obesity, hypotonia, and developmental delay.
MC1R mutant females, and females overexpressing the endogenous MC1R antagonist, agouti signalling protein, had a reduced formalin-induced inflammatory pain response, and a delayed development of inflammation-induced hyperalgesia and allodynia.
SPARC is required for the optimal and rapid differentiation of Th17 cells, accordingly we show delayed development of experimental autoimmune encephalomyelitis whose pathogenesis involves Th17.
Methyl-CpG binding protein 2 gene (MECP2) testing is indicated for patients with numerous clinical presentations, including Rett syndrome (classic and atypical), unexplained neonatal encephalopathy, Angelman syndrome, nonspecific mental retardation, autism (females), and an X-linked family history of developmental delay.
ALG8-CDG is a severe disorder characterized by dysmorphic features, failure to thrive, protein-losing enteropathy, neurologic and ophthalmologic problems, and developmental delay.
CAMTA1 should be added to the growing list of genes associated with ID/DD, especially when behavioral problems, cerebellar signs, and/or dysmorphism are also present.
COL4A1 mutations disrupt the integrity of vascular basement membranes, so predisposing to a broad spectrum of disorders including periventricular leucomalacia, haemorrhagic stroke, aneurysm formation, epilepsy and developmental delay.
CACNA1A mutations should be evaluated in infants and young children with paroxysmal tonic upgaze especially if associated with developmental delay, cerebellar signs, and other types of paroxysmal event.