The large number of autistic individuals with unaffected family members may result from spontaneous structural variation, such as deletions, duplications or inversions in genetic material during meiosis. Hence, a substantial fraction of autism cases may be traceable to genetic causes that are highly heritable but not inherited: that is, the mutation that causes the autism is not present in the parental genome.As of 2018, understanding of genetic risk factors had shifted from a focus on a few alleles to an understanding that genetic involvement in ASD is probably diffuse, depending on a large number of variants, some of which are common and have a small effect, and some of which are rare and have a large effect. The most common gene disrupted with large effect rare variants appeared to be CHD8, but less than 0.5% of autistic people have such a mutation. The gene CHD8 encodes the protein chromodomain helicase DNA binding protein 8, which is a chromatin regulator enzyme that is essential during fetal development, CHD8 is an ATP dependent enzyme. The protein contains an Snf2 helicase domain that is responsible for the hydrolysis of ATP to ADP. CHD8 encodes for a DNA helicase that function as a transcription repressor by remodeling chromatin structure by altering the position of nucleosomes. CHD8 negatively regulates Wnt signaling. Wnt signaling is important in the vertebrate early development and morphogenesis. It is believed that CHD8 also recruits the linker histone H1 and causes the repression of β-catenin and p53 target genes.
Naratriptan (trade names include Amerge) is a triptan drug marketed by GlaxoSmithKline and is used for the treatment of migraine headaches. It is a selective 5-HT1 receptor subtype agonist. It was patented in 1987 and approved for medical use in 1997. Medical uses
Naratriptan is used for the treatment of the acute migraine attacks and the symptoms of migraine, including severe, throbbing headaches that sometimes are accompanied by nausea and sensitivity to sound or light. Efficacy
A meta-analysis of 53 clinical trials has shown that all triptans are effective for treating migraine at marketed doses and that naratriptan, although less effective than sumatriptan and rizatriptan was more effective than placebo in reducing migraine symptoms at two hours and efficacy was demonstrated in almost two thirds of subjects after four hours of treatment. Side effects
Side effects include: dizziness, drowsiness, tingling of the hands or feet, nausea, dry mouth and unsteadiness. If these effects persist or worsen, notify your doctor promptly. Side-effects which are unlikely and which should be promptly reported include: chest pain/pressure, throat pain/pressure, unusually fast/slow/irregular pulse, one-sided muscle weakness, vision problems, cold/bluish hands or feet, stomach pain, bloody diarrhea, mental/mood changes, and fainting. In the unlikely event you have a serious allergic reaction to this drug, seek immediate medical attention. Symptoms of a serious allergic reaction include: rash, itching, swelling, severe dizziness, trouble breathing (swelling of the throat).