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A Robust Polymerase Chain Reaction-based Assay for Quantifying Cytosine-guanine-guanine Trinucleotide Repeats in Fragile X Mental Retardation-1 Gene
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Infant Development in Fragile X Syndrome: Cross-Syndrome Comparisons

Jane E Roberts1, Lindsay M McCary2,3, Svetlana V Shinkareva2

  • 1Department of Psychology, The University of South Carolina, 1512 Pendleton St., Barnwell College 224, Columbia, SC, 29208, USA. jane.roberts@sc.edu.

Journal of Autism and Developmental Disorders
|February 12, 2016
PubMed

Insights

Infants with fragile X syndrome (FXS) show distinct developmental delays by 6 months, differing from typical development and autism at high risk. These early and pervasive delays suggest unique developmental trajectories in FXS.

Area of Science:

  • Developmental psychology
  • Pediatric neurology
  • Genetics

Background:

  • Fragile X syndrome (FXS) is a leading genetic cause of intellectual disability and autism spectrum disorder.
  • Early identification of developmental trajectories in infants with FXS is crucial for timely intervention.
  • Understanding divergence from typical development and other high-risk groups aids in differential diagnosis.

Purpose of the Study:

  • To characterize the early developmental profile of male infants with fragile X syndrome (FXS).
  • To compare the developmental trajectory of infants with FXS against typically developing infants and infants at high risk for autism (ASIBs).
  • To identify early markers differentiating FXS from other developmental conditions.

Main Methods:

  • Cross-sectional study involving 174 male infants aged 5–28 months.
  • Utilized the Mullen Scales of Early Learning to assess cognitive and developmental skills.
  • Compared developmental profiles between infants with FXS, typically developing infants, and ASIBs.

Main Results:

  • Infants with FXS were distinguishable from typically developing and ASIB groups by 6 months of age.
  • A trend of decreasing developmental skills with increasing age was observed in infants with FXS.
  • This age-related decline in skills was unique to the FXS group compared to controls.

Conclusions:

  • Infants with FXS exhibit significant, pervasive, and early-emerging developmental delays.
  • The developmental profile of FXS appears etiologically distinct from typical development and ASIBs.
  • Early differentiation is possible, highlighting the need for targeted developmental support in FXS.

Keywords:
AutismEarly developmentFragile X syndromeInfantsMullen

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