Front Matter

More Than 1,000 Genetic and Genomic Disorders and Still Counting 29

in the typical fragrances used in the western world: these chemicals are com­
monly produced from petroleum products, and many are benzene ring prod­
ucts, which is alarming given benzene’s well‐established reputation as a
mutagenic agent (Figures 1.1 and 1.2).
Then, what causes ASD, if these chemicals that induce mutations in the fetal
brain cells do not directly cause ASD? The reasons for our opinion are two‐
fold: first, ASD is primarily not a genetic disease but a neurodevelopmental
disease with a wide spectrum, hence the name ASD; and secondly, over 98% of
our genome consists of noncoding DNA, and mutations in those parts of the
DNA may not have any consequences.
As part of our exploration of the molecular reasons why ASD has greater
prevalence in male children than in their female counterparts [12], we dis­
covered that male‐derived fetal brain cell lines are much more sensitive to
fragrances and consequently dramatically lose their arginine vasopressin‐
and oxytocin‐positive receptors that carry neurons. The loss of arginine

Frontal

lobe

Amygdala

Hippocampus

Autism and the brain

Spinal cord

Cerebellum

Thalamus

Hypothalamus

The areas of the brain affected by autism,

which stems from abnormal brain development:

Autism and the brain

Important to pro-

cessing emotions,

behavior

Involved in learn-

ing, memory

• Cells are smaller, more densely packed in certain areas


• Have shorter, less developed branches

Figure 1.17 Area of an autistic child’s brain affected by neuromodifying agents during
fetal development. Source: https://www.google.com/search?newwindow=1&hl=en&site=
imghp&tbm=isch&source=hp&biw=1264&bih=576&q=Autism+brain&oq=Autism+brain
&gs_l=img.3..0l10.2769.7284.0.9636.13.13.0.0.0.0.302.1133.11j3‐1.12.0....0...1.1.64.
img..1.12.1133.0..35i39k1.‐vVn0071Vjw#imgrc=uP1nZdh1rl2osM.