Enquire NowCall Back Whatsapp Lab report/login
Understanding Noonan Syndrome: Causes, Symptoms, and Treatment Options

Home > Blogs > Understanding Noonan Syndrome: Causes, Symptoms, and Treatment Options

Understanding Noonan Syndrome: Causes, Symptoms, and Treatment Options

Neurosciences | Posted on 11/29/2023 by Dr. Pushkar Gupta


Is there a deep groove in your child’s upper lip or has drooping eyelids? It might be an indication that your child is suffering from Noonan syndrome. It is a genetic disorder affecting the child’s development. This condition is determined to be a comparatively genetic disorder. The accurate frequency can differ depending on the different populations and geographic zones. However, according to an estimation, this condition affects one in a thousand births and often targets both women and men. 

If your child suffers from Noonan syndrome, then book your appointment with one of the best multispeciality hospitals, CK Birla Hospital in Jaipur. The team of the best and most experienced doctors will ensure proper diagnosis with the right treatment solutions.

Kindly note that the blog is for informative purposes only and we do not interfere with the doctor’s consultation in any way. 

What is Noonan syndrome? 

Noonan syndrome is one of the genetic conditions stopping the usual growth and development in different parts of the human body. This condition targets the person in many ways including facial attributes, heart issues, short height, and many other physical issues. A child can experience issues while developing such as growing slowly more than a regular child. There are other issues like walking, learning, talking, etc. While some children experience mild symptoms of Noonan syndrome, some might go through serious symptoms.

Since Noonan syndrome doesn’t have a cure, the healthcare expert suggests certain ways to keep the child healthy as much as possible. The doctor also works with the patient closely to ensure preventing complications or catching them initially. This will assist the child to lead a happy and healthy life. 

What are the symptoms of Noonan syndrome? 

Noonan syndrome symptoms differ from mild to dangerous and depending on the child’s body part it has affected the most. Usually, symptoms begin to grow when the fetus is growing in the uterus or when the child is 11. Here are some symptoms on the face that are easily noticeable: 

  • A profound groove in the upper lip
  • Tall forehead 
  • Eye color changes in blue or green
  • Ptosis or drooping eyelids 
  • Flat nose having a wide base and bulging tip
  • Downward-slanting eyes 
  • Low-set ears

There are other common symptoms that are noticeable physically:

  • Short neck having low hairline and additional skin folds
  • Finger pads or bulging toes
  • Pectus excavatum 
  • Abnormally shaped nails 
  • Short stature 

Children having Noonan syndrome also have heart conditions like congenital heart disease. Hence, on-time treatment is required to treat the problem. Children with Noonan syndrome develop heart-related symptoms gradually which include:

  • Pulmonary artery stenosis 
  • Heart muscle thickening 
  • Atrial septal defect

Some children also experience other symptoms like:

  • Developmental delays 
  • Trouble feeding children
  • Accumulation of fluid in the hands or feet 
  • Breathing problems 
  • Bleeding or bruising
  • Undescended testicles 
  • Scoliosis or a curved spine 
  • Birth disorders 
  • Vision issues 
  • Hearing loss 

What causes Noonan syndrome? 

The exact cause of Noonan syndrome is unknown but it is believed that it occurs because of mutations in the genes helping the body tissues develop. These changed genes form proteins that are supposed to be active. They interrupt with correct cell development and division. Here are two main identified Noonan syndrome causes:

  • Inherited- It is found that a parent passes this condition to the child. 
  • Spontaneous changes- These changes occur and develop without family history. 

Noonan Syndrome v/s Turner Syndrome 

Noonan syndrome and Turner syndrome are genetic disorders affecting several development aspects. However, it doesn’t imply that they are similar. Both the disorders are different conditions with different attributes. Let’s see how:

  • Noon syndrome- It is often caused by changes in genes which include RAF1, SOS1, and PTPN11, etc. This disorder involves following a pattern that is an autosomal dominant inheritance. The symptoms of the condition involve problems related to physical features and overall health. There are other symptoms as well like short stature, heart issues, bleeding issues, etc. The symptoms might vary depending on the affected individuals. 
  • Turner syndrome- It happens because of an entire or partial dearth of X chromosomes, usually in women. This condition is not inherited from the parents and typically happens as an outcome of reproductive cell formation. The symptoms of this condition are linked to physical features and clinical conditions. The common symptoms are a weblike neck, short stature, broad chest, etc. People with this condition experience reproductive anomalies like underdeveloped ovaries, causing infertility. Heart and kidney-related issues are also linked to Turner syndrome. 

In a nutshell, both Noonan and Turner syndrome have similar symptoms that are of overlapping features, and short stature, even then they occur from varied genetic anomalies and have different medical manifestations. 

How is Noonan syndrome diagnosed?

The healthcare expert might suspect Noonan syndrome after physical evaluation and reviewing the symptoms in a child. The doctor might involve certain tests to confirm the diagnosis and exclude the probability of other conditions. Here are the tests that are often ordered: 

  • CT Scan 
  • Genetic testing
  • Ultrasounds 
  • Chest X-ray
  • Echocardiogram 
  • Electrocardiogram
  • Complete blood count 

How is Noonan syndrome treated? 

The healthcare team of a child offers Noonan syndrome treatment depending on the symptoms and seriousness of the condition. Here are the most common treatment options usually involved:

  • Support for learning disabilities in education 
  • Growth hormonal therapy 
  • Supportive therapies like compression therapy 
  • Assistive devices like hearing aids or eyeglasses 
  • Medicines to resolve issues with the child’s heart, treat bleeding problems, or slow growth improvement.
  • In certain cases, there might be a need for surgery. Hence, early diagnosis is vital to receiving effective treatment and follow-up care.


There is no doubt that a clinical diagnosis can sound scary when it is about your newborn baby or a developing child. However, most children who are diagnosed with Noonan syndrome experience mild symptoms and often live life like a normal person. They remain healthy and active throughout their life. However, in certain cases, if the symptoms are severe, one must consult the doctor for effective treatment and to understand continuous care options suitable for the child’s requirements. Immediate requirements assist in relieving the concerns and ensuring that the child has the best way out. 



Is Noonan syndrome considered a disability?

Yes, Noonan syndrome is considered as an intellectual disability.

Is Noonan syndrome dominant or recessive?

Noonan syndrome has an autosomal dominant pattern as it is an inherited condition 

How is Noonan syndrome inherited?

Noonan syndrome is an inherited condition as one parent passes faulty genes to the child which increases the probability by 50% that the child will born with Noonan syndrome.