Gary M. Leong

Pediatric Endocrinologist

Male📍 Sydney

About of Gary M. Leong

Gary M. Leong is a paediatric endocrinologist based in Sydney, NSW, Australia. He looks after kids and teens with hormone and growth-related health issues, and he also helps manage complex metabolic problems that can affect daily life.


In many cases, families come in for support with growth concerns, such as delayed growth or short stature. At other times, the focus is on weight and metabolism, including childhood obesity and type 2 diabetes. He also treats conditions where the body’s hormone signals are out of balance, which can show up in different ways depending on the child.


Some patients need care for sugar and insulin regulation issues, including congenital hyperinsulinism. Others may be dealing with episodes where blood sugar becomes dangerously high, such as diabetic ketoacidosis. There are also cases linked to dehydration, where getting the right treatment early can make a big difference.


Gary also works with children who have differences in sex development, including intersex conditions and partial androgen insensitivity syndrome (PAIS). He may be involved in ongoing care for conditions like Prader-Willi syndrome, where hormone and appetite signals can affect growth and energy use.


Over time, he helps families understand what is happening in a way that fits real life at home. Hormone conditions can be stressful, especially when there are school days, sports, and changing routines. In many cases, families want clear next steps, close monitoring, and a plan that can be followed between appointments.


Gary’s practice focuses on paediatric endocrinology, with specialist training in this area. His experience also covers related complications that can happen alongside these conditions, including dehydration and short-term metabolic flare-ups. He works with the broader care team when that’s needed, so kids get coordinated support rather than a one-off visit.


For research and clinical trials, no specific trial or study details are listed here. What matters most in clinic is safe, practical care for each child’s situation, with treatment decisions based on the child’s symptoms, growth, and overall health.

Services & Conditions Treated

ObesityObesity in ChildrenCongenital HyperinsulinismDehydrationDelayed GrowthDiabetic KetoacidosisIntersexPartial Androgen Insensitivity Syndrome (PAIS)PneumomediastinumPrader-Willi SyndromeShort Stature (Growth Disorders)Subcutaneous EmphysemaType 2 Diabetes (T2D)

Publications

1 total

An Uncommon Presentation of Hamman's Syndrome in an Adolescent With Acute Diabetic Ketoacidosis and Newly Diagnosed Type 1 Diabetes.

Case reports in pediatrics • June 05, 2024

Frequently Asked Questions

What services does Dr Gary M. Leong provide?
Dr Leong is a pediatric endocrinologist in Sydney who works with conditions like obesity and obesity in children, congenital hyperinsulinism, delayed growth, short stature, and type 2 diabetes in young people, among others.
Which conditions related to growth and puberty does he treat?
He deals with growth issues such as delayed growth and short stature (growth disorders), and conditions that involve puberty and development like intersex and partial androgen insensitivity syndrome (PAIS).
Can I see Dr Leong for diabetes-related problems in kids?
Yes. He treats diabetes in children and adolescents, including type 2 diabetes, and related metabolic concerns as part of his pediatric endocrinology practice.
What are common reasons for an appointment with a pediatric endocrinologist?
Common reasons include concerns about growth, obesity in children, metabolic or hormonal issues such as diabetes, congenital conditions like congenital hyperinsulinism, and other endocrine-related concerns.
Are there concerns about dehydration or chest issues that he can help with?
Yes. His expertise covers conditions that can involve dehydration and certain chest findings like pneumomediastinum, as part of comprehensive endocrine and metabolic care when needed.
How do patients book an appointment with Dr Leong in Sydney?
Please contact the clinic where he practices in Sydney to arrange an appointment. They can provide availability and next steps for new or existing patients.