"Heritability was estimated at 73% in a community sample of 6-year-old twins, with higher rates in girls. "A childs temperament can also impact the development of SAD. Timid and shy behaviors may be referred to as "behaviorally inhibited temperaments" in which the child may experience anxiety when they are not familiar with a particular location or person. Mechanism
Preliminary evidence shows that heightened activity of the amygdala may be associated with symptoms of separation anxiety disorder. Defects in the ventrolateral and dorsomedial areas of the prefrontal cortex are also correlated to anxiety disorders in children. Diagnosis
Separation anxiety occurs in many infants and young children as they are becoming acclimated with their surroundings. This anxiety is viewed as a normal developmental phase between the months of early infancy until age two. Separation anxiety is normal in young children, until they age 3–4 years, when children are left in a daycare or preschool, away from their parent or primary caregiver. Other sources note that a definite diagnosis of SAD should not be presented until after the age of three.Some studies have shown that hormonal influences during pregnancy can result in lower cortisol levels later in life, which can later lead to psychological disorders, such as SAD. It is also important to note significant life changes experienced by the child either previous to or present at the onset of the disorder.
In other cases it is inherited from one affected parent.Loeys–Dietz syndrome was identified and characterized by pediatric geneticists Bart Loeys and Harry "Hal" Dietz at Johns Hopkins University in 2005. Signs and symptoms
There is considerable variability in the phenotype of Loeys–Dietz syndrome, from mild features to severe systemic abnormalities. The primary manifestations of Loeys–Dietz syndrome are arterial tortuosity (winding course of blood vessels), widely spaced eyes (hypertelorism), wide or split uvula, and aneurysms at the aortic root. Other features may include cleft palate and a blue/gray appearance of the white of the eyes. Cardiac defects and club foot may be noted at birth.There is overlap in the manifestations of Loeys–Dietz and Marfan syndromes, including increased risk of ascending aortic aneurysm and aortic dissection, abnormally long limbs and fingers, and dural ectasia (a gradual stretching and weakening of the dura mater that can cause abdominal and leg pain).