Emphasizing Precision & Early Care

Polygenic Height Score

Understanding why a child is short Recent medical research shows that a child’s height is shaped by many small genes working together, not just by hormones or nutrition.

Doctors can now use this information - called the Polygenic Height Score, which helps show whether a child is naturally more likely to be shorter or taller as they grow. The score helps give a more accurate estimate of a child’s expected adult height than using parents’ heights alone.

For many children who were previously told they had “no clear reason” for being short, this score provides a real biological explanation, even when both parents are of average height.

This helps parents understand that their child’s height is not caused by poor care, or anything they did wrong.

Why we also check rare genetic causes of growth problems

Sometimes, a child actually has a change in one specific gene that routine tests cannot detect. By also checking for single-gene diseases, doctors can look for known genetic conditions affecting growth, or confidently rule them out.

This includes genes linked to short height, bone and cartilage development, hormone pathways, and conditions that can cause early or delayed puberty, which can influence final height.

Clear & Reassuring

Combining Polygenic + Disease Gene Testing

We use a test called whole genome sequencing (WGS), which looks at all of your child’s DNA.

First, we calculate a Polygenic Height Score to estimate whether a child is naturally more likely to be shorter or taller as an adult. This score is adjusted for ancestry because genetic background matters.

Many Chinese families are not purely one genetic background and may have a mix of Southern or Northern Chinese, Southeast Asian, or Central Asian ancestry. Some children may also be mixed-race, for example with both European and Asian ancestry. Adjusting for ancestry helps make the height estimate more accurate and avoids misleading results.

Second, we also check for genetic diseases that can affect growth, and the result can influence medical treatment decisions (over 300 disorders). For example, some children with changes in the ACAN gene may benefit from earlier consideration of growth hormone treatment, as delayed treatment may limit final height.

In other cases, genes related to early puberty may prompt doctors to monitor puberty timing more closely or consider treatment to slow early puberty to promote adult height.

How Accurate is the Polygenic Height Score?

Large clinical studies show that when doctors use both the genetic height score and parents’ heights together, adult height prediction is most accurate: AUROC ~0.90 (Height < −2 SD).

• An AUROC of 0.9 means the test has very strong ability to distinguish between children who will grow up to be short and those who will not.

References:

1. National Library of Medicine - Is height determined by genetics? https://medlineplus.gov/genetics/understanding/traits/height/

2. A saturated map of common genetic variants associated with human height. Nature 610, 704–712 (2022).

3. Lu et al. (JCEM 2021)

4. Shelley et al. (Genome Medicine 2025)

FAQs

1. Why is my child short even though tests so far are normal?

• Many children are short because of their genetics rather than illness. Height is influenced by hundreds of small genes working together, and routine blood tests cannot see this.

• WGS looks directly at your child’s DNA to understand their natural growth potential and explains their height.

2. What does this genetic test actually look for?

This test does two things.

• First, it calculates a genetic height score to show whether your child is naturally predisposed to be shorter or taller.

• Second, it checks for rare single-gene diseases that can affect growth, bone development, or puberty.

This combined approach helps explain growth more completely than standard tests alone.

3. Does this test replace hormone testing?

• No. This test does not replace hormone testing or medical evaluations. Instead, it adds important genetic information, including a genetic height score that predicts adult height more accurately than using parents’ heights alone.

4. What does it mean if no disease gene is found?

• If no single-gene condition is found, this is usually reassuring. It means your child’s height is most likely due to natural genetic variation rather than an underlying disease.

• Doctors can focus on balanced nutrition, good sleep routines, regular physical activity to help your child reach the best height possible for their genetics.

5. How can this test help my child in the long term?

• The results help parents understand if their child is naturally expected to be shorter, reducing worry about hidden diseases, and avoid unnecessary tests.

• This clarity also helps doctors make better decisions - growth monitoring during puberty and adolescence, understanding puberty timing, and deciding whether any treatment is needed.

For Physicians

• Rainbow whole genome sequencing (WGS) covers the majority of current ACMG guideline for genetic testing associated with Idiopathic Short Stature.

• Polygenic Height Score is sensitive to underlying diseases and may be a more accurate assessment of height compared to mid-parental height.

• Our polygenic height score is adjusted for the ancestral background of the patient, and is accurate for Asians and mix-raced individuals.

• Our WGS test returns findings including single nucleotide variants, copy number variants equivalent to microarray testing, and putative UPD.

• Children with Turner Syndrome features should receive karyotyping testing first.

• Rainbow Genomics performs testing at U.S. CLIA-certified and CAP-accredited clinical laboratories. Results are specific for Asian, European and mixed-race patients.

• Our test analysis is performed by U.S. medical teams, and reports are issued by a board-certified medical director.

• Genetic counseling is provided by a dual-U.S. board-certified and Australia board-certified genetic counselor.

• Patient cohort studies, peer-reviewed articles and clinical utilities/management paths are available upon request.

  *References:

• Lu et al. (JCEM 2021)

• Shelley et al. (Genome Medicine 2025)