Sexual dimorphic effect in the genetic association of monoamine oxidase A (MAOA) markers with autism spectrum disorder

Postnatal behavioral and inflammatory alterations in female pups prenatally exposed to valproic acid

“…Remarkably, these reports show incidence is three times higher in boys than in girls. This gender bias can be partially explained by specific genetic differences between men and women (Verma et al, 2014), but other sexual differences [e.g. testosterone levels (Auyeung et al, 2009)] could play a role both in increased male susceptibility and in female resilience.…”

Serotonin mediated immunoregulation and neural functions: Complicity in the aetiology of autism spectrum disorders

“…This finding was supported by one case-control study (Yoo et al, 2009), and contradicted by another study through family and case-control approach (Yirmiya et al, 2002). Recently Verma et al (2014) reported the sexual dimorphic effect in the association of MAO-A polymorphisms with ASD and the results are suggestive of the sex ratio differences in the incidence of this disorder. The only study examining association of MAO-B with autism using small sample size reported that G allele of rs1799836, which showed higher distribution in autistic patients was associated with reduced plasma MAO-B activity in male cases (Salem et al, 2013).…”

“…The underlying mechanism for hyperserotonemia is investigated through genetic studies, mainly restricting to key regulators of 5-HT homeostasis such as tryptophan hydroxylase (TPH), 5-HT transporter (SERT), 5-HT 2A receptor and monoamine oxidases (MAO). Association studies using genes encoding proteins that regulate 5-HT levels and its activity are examined to identify genetic variants conferring susceptibility to ASD (Cohen et al, 2011;Conroy et al, 2004;Cook et al, 1997;Hranilovic et al, 2010;Kim et al, 2002;Yang et al, 2012), but inconsistent results on association made it difficult to accurately nail down an isolated gene or a group of genetic markers (Coutinho et al, 2004;Guhathakurta et al, 2006Guhathakurta et al, , 2008Jaiswal et al, 2015;Tassone et al, 2011;Verma et al, 2014). In addition to genetic analyses, researchers have used theoretical models to investigate the hyperserotonemia in autism (Anderson et al, 1987a;Janusonis, 2008).…”

Genetic Studies in Autism

“…Monoamine oxidase A (MAOA) on X chromosome is responsible for the degradation of serotonin and found to be significantly associated with ASD in a population based study. Haplotyping association showed differential effects in males and females, posing higher risk in males as compared to females [43]. Although no published data on CMA and exome sequencing on ASD are available from India, in author's personal experience, the etiological yield is better in the presence of facial dysmorphism, positive family history or presence of congenital abnormalities.…”