Table 2.
Antenatal markers for the risks of autism
|
Marker
|
Details
|
| Genetic markers | Single-gene disorders: Fragile X syndrome (FMRI mutations), neurofibromatosis (NF1), tuberous sclerosis complex (TSC1 and TSC2 mutation), Dup15q syndrome, Rett syndrome (MeCP2 mutation), 16p11.2 region deletions, SHANK3, NRXN1, CNTNAP2, and CHD8 genes mutations |
| Chromosomal Disorders: Down syndrome, aberrations on the long arm of Chromosome 15, and reciprocal chromosomal translocation between long arms of chromosomes 4 and 14 | |
| Messenger RNA (mRNA) and microRNA (miRNA) expression abnormality | |
| Abnormal DNA methylation patterns | |
| Cytokines biomarkers | Abnormal profile of interleukin-6, tumor necrosis factor-alpha, interleukin-1 receptor antagonist, TNF- α, Serpin E1, vascular cell adhesion molecule 1, vascular endothelial growth factor D, Epidermal growth factor, Colony Stimulating Factor 1, and 2 |
| Autoantibodies biomarkers | The presence of circulating maternal autoantibodies, especially anti-brain autoantibodies, during pregnancy |
| Maternal autoantibody response against Collapsin Response Mediator Protein 1 (CRMP1) | |
| Simultaneous reactivity against bands at 39 kDa and 73 kDa is associated with early-onset autism. | |
| Oxidative stress biomarkers | Maternal urinary levels of free 8-iso-prostaglandin F2α (8-iso-PGF2α) |
| Hormonal biomarkers | High prenatal testosterone levels |
| Polycystic ovary syndrome | |
| Elevated levels of steroidogenic hormones (cortisol, androstenedione, testosterone, 17α-hydroxy-progesterone, and progesterone) in amniotic fluid | |
| Mid-pregnancy thyroid-stimulating hormone (inverse relationship) | |
| Maternal nutritional biomarkers | Fetal levels of manganese and zinc |
| Abnormal zinc-copper cycles (altered rhythmicity, shorter cycle duration, reduced regularity, and diminished complexity) | |
| Vitamin D deficiency | |
| Poor folic acid intake | |
| Biophysical markers | Presence of multiple fetal abnormalities (especially cardiac, urinary, cranial, and brain anomalies) |
| Presence of a narrower head and a relatively broader ocular distance | |
| Altered prenatal brain growth | |
| Abnormal Kurjak's antenatal neurodevelopmental scoring test in the last trimester | |
| Radiological profile | Isolated ventriculomegaly |
| Altered cortical development | |
| Enlarged insula lobe | |
| Increased amygdala volume and fast growth rate |
CHD8: Chromodomain helicase DNA binding protein 8; CNTNAP2: Contactin Associated Protein 2; Dup15q syndrome: Duplications of the portion of 15q11.2-13.1 chromosome; kDa: Kilodalton; MeCP2 mutation: Mutations of the methyl-CpG binding protein 2; NRXN1: Neurexin 1 RNA: Ribonucleic acid; SHANK3: SH3 and multiple ankyrin repeat domains 3; TNF-α: Tumor Necrosis Factor Alpha; TSC1: Tuberous sclerosis complex 1; TSC2: Tuberous sclerosis complex 2.