Baby Sibs

Recurrence Risk for Autism Spectrum Disorders: A Baby Siblings Research Consortium Study

Source: 
Pediatrics, Ozonoff et al.
Date Published: 
August 2011
Year Published: 
2011

A study published August 15, 2011 in the journal Pediatrics found that infants with an older autistic sibling have a near 19 percent risk that they too will develop the disorder. The study is considered the largest autism study to follow infants for sibling recurrence.

Autism Risk Linked To Space Between First And Second Pregnancy

Source: 
Medical News Today
Date Published: 
January 10, 2011
Abstract: 

A second child is three times more likely to be diagnosed with autism if they are born within twelve months of their siblings, compared to those born three or more years apart, researchers from the Lazarsfeld Center for the Social Sciences at Columbia University, New York revealed in the journal Pediatrics. The investigators gathered information on 660,000 second children born in California between 1992 to 2002.

Neural Signatures of Autism

Source: 
PNAS, Kaiser, Hudack, Schultz, Lee, Cheung, Berken, Deen, Pitskel, Sugrue, Voos, Saulnier, Ventola, Wolf, Klin, Vander Wyk, Pelphrey
Date Published: 
December 2010
Year Published: 
2010

These findings of this study hold far-reaching implications for our understanding of the neural systems underlying autism. Using FMRI to record the biological motion of children with autism spectrum disorder, unaffected siblings of children with ASD, and typically developing children, the study reveals three types of neural signatures: The study finds distinct brain responses to biological motion exhibited by typical developing children and unaffected siblings. This finding is particularly striking given the identical behavioral nature of these two groups.

Siblings of Autistic Children May Have Some Autism Related Traits, Study Says

Source: 
LA Times
Date Published: 
October 11, 2010
Abstract: 

Scientists at the Washington University School of Medicine have uncovered more evidence of a genetic basis for autism. Reviewing surveys collected from more than 1,000 families with autistic kids, they discovered that siblings of autistic children who have not been diagnosed with the disease often exhibit mild traits of autism, including speech delays.

Infants Gaze May Be an Early, but Subtle, Marker for Autism Risk

Source: 
Science Daily
Date Published: 
September 1, 2010
Abstract: 

Kennedy Krieger Institute have announced new study results showing an early marker for later communication and social delays in infants at a higher-risk for autism may be infrequent gazing at other people when unprompted. The study also found that six-month-old high-risk infants demonstrated the same level of cause and effect learning skills when compared to low-risk infants of the same age.

Autism's Earliest Symptoms Not Evident in Children Under 6 Months

Source: 
Science Daily
Date Published: 
February 16, 2010
Abstract: 

A study of the development of autism in infants, comparing the behavior of the siblings of children diagnosed with autism to that of babies developing normally, has found that the nascent symptoms of the condition -- a lack of shared eye contact, smiling and communicative babbling -- are not present at 6 months, but emerge gradually and only become apparent during the latter part of the first year of life.

Structural Variation of Chromosomes in Autism Spectrum Disorder

Source: 
American Journal of Human Genetics, Marshall, Noor, et al
Date Published: 
2008
Year Published: 
2008

Structural variation (copy number variation [CNV] including deletion and duplication, translocation, inversion) of chromosomes has been identified in some individuals with autism spectrum disorder (ASD), but the full etiologic role is unknown. We performed genome-wide assessment for structural abnormalities in 427 unrelated ASD cases via single-nucleotide polymorphism microarrays and karyotyping. With microarrays, we discovered 277 unbalanced CNVs in 44% of ASD families not present in 500 controls (and re-examined in another 1152 controls). Karyotyping detected additional balanced changes. Although most variants were inherited, we found a total of 27 cases with de novo alterations, and in three (11%) of these individuals, two or more new variants were observed. De novo CNVs were found in approximately 7% and approximately 2% of idiopathic families having one child, or two or more ASD siblings, respectively. We also detected 13 loci with recurrent/overlapping CNV in unrelated cases, and at these sites, deletions and duplications affecting the same gene(s) in different individuals and sometimes in asymptomatic carriers were also found. Notwithstanding complexities, our results further implicate the SHANK3-NLGN4-NRXN1 postsynaptic density genes and also identify novel loci at DPP6-DPP10-PCDH9 (synapse complex), ANKRD11, DPYD, PTCHD1, 15q24, among others, for a role in ASD susceptibility. Our most compelling result discovered CNV at 16p11.2 (p = 0.002) (with characteristics of a genomic disorder) at approximately 1% frequency. Some of the ASD regions were also common to mental retardation loci. Structural variants were found in sufficiently high frequency influencing ASD to suggest that cytogenetic and microarray analyses be considered in routine clinical workup.