Temple Syndrome is a rare genetic condition impacting an individual’s growth and development. Its features and severity vary among individuals. This article provides insights into its genetic basis, common characteristics, diagnostic methods, and management strategies.
Understanding Temple Syndrome
Temple Syndrome is an imprinting disorder, meaning gene expression depends on whether they are inherited from the mother or father. The condition stems from a genetic alteration on chromosome 14, specifically within the 14q32 imprinted region.
Genetic changes typically involve maternal uniparental disomy of chromosome 14 (UPD14), where an individual inherits two maternal copies and no paternal copy. Other causes include a deletion of the paternally inherited 14q32 copy, or an altered epigenetic state like hypomethylation at the IG-DMR imprinting control region. These alterations lead to an imbalance, causing either overexpression of maternally expressed genes or a lack of expression of paternally expressed genes in this region. The genes DLK1 and RTL1 are implicated, and their altered expression contributes to the syndrome’s features.
Recognizing the Features
Individuals with Temple Syndrome present with various clinical features affecting growth and development. Prenatal growth restriction is common, leading to low birth weight, which often continues as postnatal growth failure and short stature. Feeding difficulties are frequently reported during infancy, sometimes resulting in a diagnosis of failure to thrive.
Low muscle tone (hypotonia) is a common finding, impacting motor skill development like delayed walking. Developmental delays, particularly in motor skills and speech, are also observed, though severity varies. Distinctive facial features may include a prominent forehead, a short nose with a wide tip, downward-turning mouth corners, a small jaw (micrognathia), and a high-arched palate. Other physical characteristics include small hands and feet, and some individuals may develop central obesity in childhood, sometimes associated with excessive hunger.
Navigating Diagnosis
Diagnosis of Temple Syndrome typically begins with a clinical evaluation by a genetic specialist, based on observed physical characteristics and developmental patterns. This assessment considers features like growth restriction, hypotonia, and developmental delays. The syndrome’s rarity and variable presentation can make early diagnosis challenging, as symptoms may overlap with other conditions like Silver-Russell syndrome.
Confirmation relies on specific genetic testing to identify the underlying alteration on chromosome 14. Molecular genetic methods, such as methylation analysis, detect the methylation status at the IG-DMR, which often appears hypomethylated. Other tests like chromosomal microarray can identify deletions or extensive uniparental disomy, though they may not detect all types of associated genetic alterations.
Support and Management Strategies
Managing Temple Syndrome involves a comprehensive, multidisciplinary approach. Physical therapy improves muscle tone and motor development, aiding strength and coordination. Occupational therapy assists with fine motor skills, daily living activities, and sensory processing. Speech therapy addresses communication delays and feeding difficulties, including infant sucking reflexes.
Nutritional support is important for growth concerns and feeding challenges, ensuring adequate calorie and nutrient intake. Early intervention programs provide specialized therapies and educational support from a young age. Individualized educational plans (IEPs) tailor learning environments to meet specific developmental needs, which can vary from mild to severe intellectual disability in some cases. Regular medical follow-ups with specialists, including a pediatrician and pediatric endocrinologist, monitor growth, development, and address conditions like early onset of puberty, which might require growth hormone or GnRH agonist therapy.
Outlook and Quality of Life
Temple Syndrome is a lifelong genetic condition, but many individuals achieve significant developmental progress with consistent support. Early and ongoing interventions, including therapies and educational programs, substantially improve outcomes. Growth hormone therapy, for instance, has shown short-term improvements in height standard deviation scores for patients with short stature, with some studies indicating normalization of height SDS over five years of treatment and improved body composition.
The long-term outlook indicates that while intellectual and developmental disabilities can occur in some cases, a notable percentage of affected individuals attend college or secure employment in adulthood. Ongoing support systems, including community resources and advocacy groups, benefit individuals and their families. These resources enhance quality of life by providing access to information, support networks, and continued specialized care, which can include monitoring for conditions like hypercholesterolemia and diabetes mellitus.