Twenty individuals reported previously with rare missense or nonsense mutations or other coding disturbances of the FMR1 gene ranged in age from infancy to 50 years; most were verbal with limited speech, had autism and hyperactivity, and all had intellectual disability.
The authors have recently shown that Fmr1KO mice with a yeast artificial chromosome containing the human FMR1 gene have corrected or overcorrected abnormal behaviors including hyperactivity and altered social interactions.
These results suggest abnormal neuronal activity in the Fmr1-KO mouse during SWRs, and hyperactivity during other wake and sleep states, with likely adverse consequences for memory processes.
Next-generation sequencing identified somatic inactivating mutations of TSC2 (3/5 tumors tested) or activating mutations of MTOR (2/5) as the primary molecular alterations, consistent with hyperactive mTOR complex 1 signaling which was further demonstrated by phospho-S6 and phospho-4E-BP1 immunostaining.
Based on logistic regression and QTDT, the 5-repeat allele of DRD4 may confer protection for hyperactive-impulsivity symptom severity compared to the 4-repeat allele.
Our findings suggest a contribution of DRD4 7R rare variants to high hyperactivity-inattention scores in a population-based sample from a large birth cohort.
Speculative hypotheses [Swanson and Castellanos, NIH Consensus Development Conference: Diagnosis and Treatment of Attention Deficit Hyperactivity Disorder, November 1998. p. 37-42] have suggested that specific alleles of these dopamine genes may alter dopamine transmission in the neural networks implicated in ADHD/HKD (e.g. that the 10-repeat allele of the DAT1 gene may be associated with hyperactive re-uptake of dopamine or that the 7-repeat allele of the DRD4 gene may be associated with a subsensitive postsynaptic receptor).
The most statistically significant gene-by-dose interactions were observed on hyperactive-impulsive symptoms for DRD4 and DAT polymorphisms, with participants lacking the DAT 10-repeat allele showing greater improvements in symptoms with increasing dose compared with 10-repeat carriers (p = .008) and those lacking the DRD4 4-repeat allele showing less improvement across MPH doses compared with 4-repeat carriers (p = 0.02).
These studies establish germline KRAS mutations as a cause of human disease and infer that the constellation of developmental abnormalities seen in Noonan syndrome spectrum is, in large part, due to hyperactive Ras.
The Raf-MEK-ERK1/2 pathway is hyper-activated in a large fraction of colorectal cancers due to mutations in K-Ras and we show that treatment of CRC cell lines with MEK inhibitors causes an increase in Cdx2 expression.
High-throughput behavioral profiling identifies nighttime hyperactivity in cntnap2 mutants, while pharmacological testing reveals dysregulation of GABAergic and glutamatergic systems.
Monocytes from HD subjects expressed mutant huntingtin and were pathologically hyperactive in response to stimulation, suggesting that the mutant protein triggers a cell-autonomous immune activation.
In alemtuzumab-induced TD, the autoantibodies against the thyrotropin receptor (TRAb) play a major role, and 2 main aspects distinguish this condition from the spontaneous form: (1) up to 20% of GD cases exhibit a fluctuating course, with alternating phases of hyper- and hypothyroidism, due to the coexistence of TRAb with stimulating and blocking function; (2) TRAb are also positive in about 70% of hypothyroid patients, with blocking TRAb responsible for nearly half of the cases.
We previously reported that hyperactive NS-causing SHP2 mutants impair the systemic production of insulin-like growth factor 1 (IGF1) through hyperactivation of the RAS/extracellular signal-regulated kinases (ERK) signalling pathway.
Patients with GNAO1 mutations can present with a severe, progressive hyperkinetic movement disorder with prolonged life-threatening exacerbations, which are refractory to most anti-dystonic medication.
The presence of CHD was related with neonatal hospitalisation (P=.04), hearing loss (P=.002), mortality (P=.09) and lower hyperactivity (P=.02), it being more frequent in HDAC8+ patients (60%), followed by NIPBL+ (33%) and SMC1A+ (28.5%).