Somatic Physiology in the Behavioral Expression of 22q11 Deletion Syndrome Open Access

Abstract

The 22q11 deletion syndrome (22q11DS), also known as velocardiofacial

syndrome or DiGeorge syndrome, is one of the most common chromosomal disorders,
with a rate of approximately 1 in 4,000 births (1). With a highly variable phenotype, this
deletion has the potential to affect almost every system in the body and can cause a wide
range of health problems. Common presentations of this disorder include cardiac defects,
endocrine dysregulation, cleft palate, and immune dysfunctions. Many studies have also
found that this population has an elevated risk for developing a range of psychiatric
illnesses and behavioral difficulties. Therefore, this study aimed to examine and
understand the role of peripheral illnesses as a possible determinant of autism spectrum
disorder (ASD) behavioral phenotypes in 22q11DS patients.
Using regression modeling with forward selection in SAS 9.2, we found that
among patients with 22q11DS, levels of IgG were significantly negatively correlated
with Aberrant Behavior Checklist (ABC) scores (β=-0.029, SE=0.01, Adjusted R2= 0.32,
P=0.04). Furthermore, the CD4+/CD8+ T cell ratio had a positive correlation with ADI-
R Restricted, Repetitive, and Stereotyped Behaviors and Interests score (p=0.0546), and
alone accounted for 18.08% of the variability in this score. Regression analysis also
revealed that lower serum calcium levels predicted more frequent social problems as
determined by the ADI-R Social total score after adjusting for gender and age at
assessment (β=-5.10, SE=1.74, P=0.015). We also found an association between higher
thyroxine and lower scores on the Communication and Symbolic Behavior Scales
(CSBS-DP) scores, which indicates concern about behavioral development. A number
of mechanisms could account for the disparity of psychological outcome among this
genetically susceptible cohort of 22q11DS patients. Our results suggest that the immune
system ties physiological and psychological factors together, which underscores the
importance of brain-immune interactions in ASD pathophysiology. Serum calcium levels
and thyroxine levels further tie together endocrine dysfunction and ASD symptoms.
Therefore, elucidating these pathways should help in understanding the mechanisms by
which behavioral changes take place among patients with 22q11DS, and ultimately lead
to strategies to control and prevent adverse psychological outcomes in this population.

Table of Contents

INTRODUCTION ...............................................................................................................1
BACKGROUND/ LITERATURE REVIEW .....................................................................3
METHODS ........................................................................................................................15
RESULTS .........................................................................................................................25
DISCUSSION ....................................................................................................................32
STRENGTHS AND LIMITATIONS ...............................................................................37
FUTURE DIRECTIONS ...................................................................................................39
CONCLUSION .................................................................................................................40
REFERENCES ..................................................................................................................42
TABLES ...........................................................................................................................50
FIGURES AND FIGURE LEGENDS ..............................................................................68
APPENDIX .......................................................................................................................74

About this Master's Thesis

Rights statement

• Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.

School	Rollins School of Public Health
Department	Epidemiology
Degree	MPH
Submission	Master's Thesis
Language	English
Research Field	Psychology, Psychobiology Health Sciences, Public Health Health Sciences, Mental Health
Keyword	thyroid t cells parathyroid Digeorge immunoglobulin schizophrenia Autism 22q11 calcium immunology velocardiofacial
Committee Chair / Thesis Advisor	Pearce, Brad, Emory University
Partnering Agencies	Emory University schools, faculty or affiliated programs Hospital or other health care provider

Last modified

Primary PDF

Thumbnail	Title	Date Uploaded	Actions
	Somatic Physiology in the Behavioral Expression of 22q11 Deletion Syndrome ()	2018-08-28 16:23:36 -0400	Press to Select an action Download

Supplemental Files

Thumbnail	Title	Date Uploaded	Actions