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Sher Ling’s story: Life with activated PI3K delta syndrome type 2 (APDS2):

Sher Ling Hineata Chong is 22 years old and a university student living in Wellington, New Zealand. Sher also has activated PI3K delta syndrome (APDS).

Sher Ling shares with us her journey to diagnosis, her strong belief in advocating for APDS awareness and research, and how she found support from others with APDS around the world through online advocacy groups.

PI3K delta syndrome Sher Ling story
Sher Ling
a 16 year journey to diagnosis APDS

A 16-year journey to a confirmed APDS diagnosis

PI3K delta syndrome Sher Ling story

“All through childhood I would get recurring ear infections and would be at the doctors for antibiotics fortnightly.”

Sher Ling’s repetitive sinus infections as a young child, also referred to as sinopulmonary infections, are a prototypical clinical manifestation of APDS in children. (Sinopulmonary infections are defined as infections of the sinuses, ears or lungs.) An estimated 96–100%1,2,3,4 of people with APDS present recurrent sinopulmonary infections. Sher Ling’s numerous ear infections led to ear graft surgery, also known as tympanoplasty, to repair the eardrum.

Like other children with APDS, Sher Ling also presented failure to thrive (FTT) in her delayed physical growth.

Sher Ling’s otorhinolaryngologist, otherwise known as an ear, nose and throat (ENT) doctor, sent Sher Ling for coeliac testing to rule it out as a possibility for her delayed growth. “When my coeliac test results came back, I was diagnosed under the broad term of a primary immunodeficiency (PI). This is because the immunoglobulins (IG) that are tested for coeliac disease were extremely low in my test results,” Sher Ling explains.

Immunoglobulins (IG) are also known as antibodies. They help identify and fight bacteria and viruses.

Following this, Sher Ling was sent for further testing which revealed she had extremely low levels of the antibodies referred to as IgG, IgA and IgE, and extremely high levels of immunoglobulin M (IgM). A positive IgM test may indicate that an individual has had a recent infection, as it is usually the first antibody produced by the immune system when a virus enters the body. High IgM levels are also a risk factor for developing recurrent infections. Following these results, Sher Ling now receives IgG immune therapy to help manage her symptoms.

Genetic Testing  advocating for APDS awareness

Hunting for a definitive and accurate diagnosis

“My genetic testing data was sent to researchers around the world for testing with the hopes of a more definitive diagnosis.”

APDS is caused by either a gain-of-function causing variation in the PIK3CD gene that encodes PI3Kδ catalytic subunit p110δ (APDS1) or by a loss-of-function causing variation in the PIK3R1 gene that encodes regulatory subunit p85α (APDS2). In both cases this leads to hyperactive PIK3 delta pathway signalling, which is the hallmark and root cause of APDS

In 2016, just three years after APDS was first classified, Sher Ling received a diagnosis of APDS type 2 (APDS2). She was 16 years old. Sher Ling is the first person in her family to have APDS, meaning it was not genetically passed on to her. This is called a de novo variant. Since her diagnosis, Sher Ling continues to see an ENT specialist and an immunologist to manage her condition.

Making global connections in the APDS community advocating for APDS awareness

The importance of social networks to meet others who can relate

Sher Ling is the first individual in her family to have APDS, and is believed to be one of just a few people with APDS identified in New Zealand. 

During the first two years after diagnosis, Sher Ling was unable to find another individual in her country with the same diagnosis. However, thanks to advocacy groups on social media, Sher Ling is now connected with another New Zealander with APDS. The pair met through a Global APDS Facebook page, a private group for individuals with APDS and their families to share non-professional advice and support.

Sher Ling is also part of a support group for adults with PIs. “It’s been awesome having that support from people going through similar things,” Sher Ling explains. However, Sher Ling feels support is missing for teenagers with APDS. “There is a lot of support for children and adults, but I have found little support for teenagers.”

“APDS has impacted my social life greatly. I can’t go out as much as I would like to as I get sick easily and it often takes me a fortnight to recover.”

Just like many others living with rare diseases, Sher Ling has experienced social limitations due to her chronic condition. “I’m pretty stubborn though, so I often end up powering through, although that has landed me in hospital a few times now,” she says.

Planning for her Future Sher ling on APDS
advocating for APDS awareness

Looking positively to the future 

Although Sher Ling continues to face obstacles with her condition, she is an independent young woman engaged with her education and the local community.

A successful university student, Sher Ling is studying to achieve a Bachelor of Sciences degree, majoring in biology and marine biology. She is now in her final semester and is planning for her next career step. Sher Ling currently lives with her brother, her flatmate and her dog, Marley, and is an active member at her local church, where she volunteers in youth work during her spare time.

advocating for APDS awareness

Research and advocacy – vital to improving outcomes for people with APDS 

Sher Ling believes research into finding a cure should be a top priority to improve the quality of life for individuals with APDS. She would also like to see further research into improving hematopoietic stem cell transplants (HSCT) for individuals with APDS, as well as research into improving symptom management medication. Sher Ling is not currently involved in any APDS research but expresses interest in engaging in future research.

“Advocacy is so important to me. I truly believe there are many undiagnosed people with APDS globally. Advocacy will help people learn about the disease and the signs to look out for.”

Activated PI3K delta syndrome (APDS) is a primary immunodeficiency (PI). It may also be referred to as a , primary immunodeficiency disorder (PID), primary immune regulatory disorder (PIRD) an inborn error of immunity (IEI) and was previously known as PASLI disease.


[1] Maccari ME, et al. Front Immunol. 2018;9:543   
[2] Coult er TI, et al. J Allergy Clin Immunol. 2017;139(2);597-606
[3] Elkaim E, et al. J Allergy Clin Immunol. 2016;138(1):210-218
[4] Carpier JM, Lucas CL. Front Immunol.2018;8:2005

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