Autism Spectrum Disorders (ASD)

autism by the numbers

*1991-1 in 500 children *2000-1 in 150 *2006-1 in 110 *2012-1 in 88 *autism now affects more people than those with diabetes, AIDS, cancer, celebral palsy, cystic fibrosis, muscular distrophy, and down syndrome combined *boys 5x more likely to have than girls

autism and vaccines

*1998 article by a British physician scared the world when he published a study that related inflammatory bowel disease, autism, and the MMR vaccine *however, it was found that the doctor falsified his data for personal gain, thus, this implication that vaccines can cause autism is false

Rett Syndrome

*almost always in girls *may have trouble walking and speaking *may exhibit repetitive behaviors (normally involving hands) *may also have intellectual disability *can suffer from motor deterioration later in life (apraxia) *80% have mutation on X chromosome *may avoid eye contact *hypotonia-weakened muscle tone *may also experience seizures

Asperger's Syndrome

*also no longer "official diagnosis" *"high-functioning"-no major cognitive difficulties, IQ's normal or above *have trouble identifying and expressing feelings *difficulty connecting with others, don't hold eye contact, have trouble reading faces and gestures *need to follow schedules rigidly *sensitivity to sounds or foods *intense interests in certain subjects *may have special ability in rare cases (drawing, math, music, etc.)

fragile-x syndrome and autism

*disorders that have abnormalities of the chromosomes, when combined account for 10-15% of autism diagnoses *X-linked recessive chromosomal disorder *largest single-gene cause of autism *60% of those with syndrome will have ASD

early studies in brain abnormalities and autism

*early studies indicated that the cerebellum (region of brain that controls coordination of movements) may be undersized. *limbic system (controls feeling, behavior, learning, processing information, and memory) seemed to have abnormalities *thus, autistics rely upon rote memory and fail to develop representational memory, which normally occurs around 2

epigenetic changes in sperm and autism

*epigenetic traits-those that are inherited, but not by changes in DNA sequence (as it it with most traits) *environmental influences, such as infections or exposure to chemicals, can cause epigenetic changes that can be passed through sperm *2015 study identified 193 high-risk istes in DNA from sperm that lead to increased risk of autism

autism spectrum disorder (ASD)

*first believed to be a psychological disorder, but now understood to be developmental disorder *appear normal at birth, but by age 2, become withdrawn, which limits childhood experiences, thus limiting growth and development *three affected areas: communication, social interaction, and repetitive behaviors

senses in autism

*for most autistics, sounds are louder, colors brighter, and touch is a disturbing intrusion *study indicates that many also suffer from synesthesia

social symptoms of autism

*may be due to lower levels of resopression, hormone that regulates social behavior *difficulty engaging in ordinary human interactions *seem indifferent to others and prefer being alone *trouble interpreting what others are thinking and feeling, as well as subtle social cues *difficulty seeing things from another's perspective *difficulty regulating their emotions *sometimes disruptive and physically agressive *have tendency to lose control, especially in strange environment *prefer structured routines and order

autism and sensory nerves

*mice studies show that some of genes linked to autism also affect sensory nerves throughout body *altered mice showed signs of heightened anxiety, perhaps from altered sense of touch

some causes of autism

*most are idiopathic (unknown cause) *not due to upbringing ("refrigerator moms") *preeclampsia-high blood pressure during late pregnancy *hereditary

classic autism ("autism disorder")

*most severely affected type *has most of social, communication, and behavioral issues typical of autistics

red flags of autism

*no big smiles or warm, joyful expressions by 6 mos. or after *no back-and-forth sharing of sounds, smiles, or facial expressions by 9 mos. or after *no babbling by 12 mos. *no back-and-forth gestures, such as pointing, showing, reaching, or waving, by 12 mos. *no words by 16 mos. *no two-word meaningful phrases (without imitating or repeating) by 24 mos. *any loss of speech, babbling, or social skills at any age

PDD-NOS (Pervasive Developmental Disorder)

*no longer "official" diagnosis *exhibit some, but not all of classic autism symptoms *some symptoms better, others worse, depends on child *sometimes referred to as "milder form" or "autism light" *share similarities with ADHD

"common genetic variation"

*refers to differences in genes that are also found in many individuals who do not have autism and by themselves are not sufficient to cause autism *however, when multiple genetic risk factors are found in same person, they combine to have a major effect on how the brain develops

paternal age and autism

*research indicates that children of older fathers (>45) may have a higher risk of psychiatric disorders, including ASD

autism and neurotransmitters

*research shows direct link between secerity of autism symptoms and brain levels of neurotransmitter GABA *autistics have trouble filtering irrelevant sensory information, which correlates to lower levels of GABA *goal is to develop medication to ease symptoms

autism and shank 3 gene

*shank 3 gene encodes protein found at synapses between nerve cells across which information flows. gene connects receptors for neurotransmitters with the inner workings of the cell *small number of autistics have been found to be missing this gene, and other autistics may have a mutated gene *in mice experiments, when gene switched, mice's social aversion and repetitive behaviors reversed

communication difficulties in autism

*some autistics remain mute throughout their lives *others delayed in language development until 5-9 *some may have to communicate with pictures or sign language *some only speak single word or communicate with pictures or sign language *have trouble with the normal "give and take" of conversations *may often talk a lot about their favorite subjects *inability to understand body language, tone of voice, or "figures of speech" *facial expressions, movements, and gestures may not match what they say *tone of voice may not reflect feelings *aversion to loud sounds or noises

potential autism drug?

*some researchers believe that a heightened stress response in neurons may underlie some traits of autism *used suramin (antipurinurgic drug for African Sleeping Sickness) on mice with autistic symptoms, helped them overcome aversion to novelty, corrected defective metabolic pathways *another used sulforaphane from broccoli sprouts to provide temporary reduction of oxidative stress

autism, an autoimmune disease?

*studies show that 23% of women tested who have autistic children had autoantibodies to brain antigens incolved in fetal brain development *chronic inflammation also associated with autism *maternal infection (especially in first trimester) increases risk of autism in child *epidemic increases in inflammatory diseases over past 60 years have correlated with rise in autism

autism and the brain

*studies show that autism, ADHD, and OCD share some genetic roots, as well as brain structure *comparison of brain structure across these conditions shows the all are associated with disruption of the corpus callosum (connects left and right regions of brain) *unique aspects of each condition might arise from other brain attributes

gestational diabetes and autism

*study found that gestational diabetes early in pregnancy increases autism risk by 40% *autism risk also higher when pregnant woman has type 2 diabetes *mothers who are obese during pregnancy have almost 2x risk of having a child with autism

genetics of autism

*twin studies indicate that 74-98% of autism cases can be attributed to genetics *one study indicates a link between autism genes and intelligence

polycystic ovaries and autism

*women with polycystic ovarian syndrome (PCOS) have increased risk of having children with autism *suspect conditions that boost androgen (male sex hormone) levels or upset hormone balance may alter brain formation in ways that contribute to social deficits, delayed language development, etc.

later studies in brain abnormalities and autism

1. autistic kids more likely to have disorganized patches of neurons in prefrontal cortex 2. another study showed that there was very little difference between brains of normal men and those with ASD 3. another study found autistics have significantly higher numbers of neurons in their brains, due to lack of "synaptic pruning." causes over-stimulation

synesthesia

a condition of intertwined perception in which one sense stimulates another sense *caused by overabundance of connections between neurons, similar to proposed case of autism *most common: "grapheme-color synesthesia"-black letters appear in colors and "sound colors" (sounds evoke colors)

autism diet

gluten-free/ casein-free (protein in cow's milk) diet *in autism, parially broken-down proteins (peptides) are absorbed into blood *peptides from gluten and casein resemble morphine, which binds to receptors in brain that might manifest in autism symptoms

autism and microbiome

in a 2016 study, the microbiomes of autistics were compared with normal kids. stool samples from autistics contained four organisms associated with autism, which did not appear in stools of unaffected siblings

applied behavioral analysis (ABA)

intense treatment of autism as early as possible *refusal to let child withdraw *rewards for correct behavior *must teach basics of body language, reactions, conversation, language, and imitation

echolalia

repeating or "parroting" what one hears

autism and gut microbes

several studies have shown that children with autism had accompanying GI problems and distinct, less diverse get microbial compositions, but could be due to the picky diet of autistic kids

autism and inflammation

studies have also clearly shown that environment can influence genetics. mothers who reported either a fever or infection during pregnancy had significantly more autism symptoms