Temple syndrome

Temple Syndrome (TS), also known as Maternal Uniparental Disomy of Chromosome 14 Syndrome (UPD(14)mat), is a rare genetic disorder characterized by pre-and postnatal growth delay, feeding difficulties, and distinct physical and developmental abnormalities. The condition is caused by genetic or epigenetic alterations involving chromosome 14, leading to disrupted expression of imprinted genes.

Clinical features

Temple Syndrome presents with a wide array of clinical signs and symptoms that vary among individuals. Common features include:

Growth and development

• Growth delay: Pre-and postnatal growth retardation is a hallmark of the condition.
• Muscular hypotonia: Reduced muscle tone leads to motor developmental delays.
• Developmental Delay: Delayed motor milestones, often accompanied by mild intellectual disability.

Feeding and metabolism

• Feeding difficulties: Infants may struggle with feeding, leading to poor weight gain.
• Childhood-Onset Central Obesity: Excessive weight gain during childhood despite earlier feeding challenges.

Skeletal abnormalities

• Bone anomalies:
  • Small hands and feet.
  • Dolichospondyly: Abnormally long and slender vertebrae.
  • Slender long bones.
  • Craniofacial disproportion.

Facial dysmorphism

Distinct facial features often observed include:

• Broad, prominent forehead.
• Short nose with a flat nasal root and wide tip.
• Downturned corners of the mouth.
• High-arched palate.
• Micrognathia: Small jaw.

Puberty and hormonal abnormalities

• Premature Puberty: Early onset of puberty is frequently reported.

Genetics and pathophysiology

Temple Syndrome is primarily caused by disruptions in the imprinting process on chromosome 14q32. This region contains several imprinted genes critical for growth and development. Specific genetic or epigenetic abnormalities include:

• Maternal Uniparental Disomy (UPD(14)mat): Both copies of chromosome 14 are inherited from the mother instead of one from each parent.
• Epigenetic Changes: Alterations in DNA methylation affecting imprinted gene expression.
• Structural Abnormalities: Microdeletions or duplications in the chromosome 14q32 region.

These abnormalities lead to improper expression of genes essential for normal development, including those regulating growth, metabolism, and skeletal formation.

Diagnosis

Temple Syndrome is diagnosed through a combination of clinical evaluation and genetic testing:

Clinical evaluation:

• Identification of characteristic features such as growth delay, facial dysmorphism, and developmental abnormalities.
• Assessment of feeding difficulties and hormonal irregularities.

Genetic testing:

• Methylation-specific PCR or other techniques to detect abnormalities in chromosome 14q32.
• Detection of maternal uniparental disomy through chromosomal microarray analysis or karyotyping.

Management and treatment

Currently, there is no cure for Temple Syndrome. Treatment focuses on managing symptoms and improving the quality of life:

Nutritional support:

• Address feeding difficulties with nutritional therapy or feeding tubes if necessary.
• Monitor for and manage obesity in childhood.

Developmental and educational interventions:

• Early physical therapy and occupational therapy to address motor delays and hypotonia.
• Individualized educational plans for intellectual and developmental support.

Hormonal therapy:

• Management of premature puberty with gonadotropin-releasing hormone agonists (GnRH agonists).

Orthopedic monitoring:

• Regular evaluation of bone abnormalities and skeletal growth.

Prognosis

The prognosis for individuals with Temple Syndrome depends on the severity of the condition and the effectiveness of symptom management. While some individuals achieve developmental milestones and lead relatively independent lives, others may require ongoing support for intellectual and physical challenges.

Epidemiology

Temple Syndrome is an extremely rare condition, with only a small number of cases reported worldwide. Its true prevalence may be underestimated due to underdiagnosis or misdiagnosis.

Research Directions

Ongoing research aims to:

• Understand the specific roles of imprinted genes on chromosome 14q32.
• Develop targeted therapies to address the underlying genetic and epigenetic abnormalities.
• Improve early diagnostic tools to identify Temple Syndrome in affected individuals.

See also

• Genetic disorders
• Growth delay
• Imprinting (genetics)
• Maternal uniparental disomy

NIH genetic and rare disease info

• NIH info on Temple syndrome

Temple syndrome is a rare disease.

Temple syndrome Resources
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