ISS
Also written as: ISS — Idiopathic Short Stature
Idiopathic short stature - short stature without an identifiable underlying pathological cause.
Full Definition
Idiopathic short stature (ISS) is a diagnosis of exclusion used when a child has short stature (typically more than 2 standard deviations below the mean height) but no identifiable underlying medical condition. Children with ISS have normal growth hormone secretion, normal thyroid function, no chromosomal abnormalities, and no evidence of chronic disease. They typically have normal growth velocity but remain consistently short throughout childhood. ISS represents a heterogeneous group that may include children with subtle genetic variants affecting growth, mild nutritional deficiencies, or simply representing the lower end of the normal height distribution. Treatment with growth hormone is controversial and approved in some countries but not others, as these children are not technically growth hormone deficient.
Usage
Usage note: Always spell out on first use; ensure thorough evaluation has been completed before this diagnosis.
In Context
- "After extensive evaluation, the patient was diagnosed with ISS as no underlying pathology was identified." — Endocrine consultation summary
- "ISS remains a diagnosis of exclusion requiring comprehensive evaluation to rule out treatable causes." — Clinical guideline