Diagnosing Genetic Syndromes

Dr. Iannelli Discusses What Qualifies as a Genetic Syndrome

doctor examining boy while mother looks on
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A mother brought her 14-year-old son into my office to ask about diagnosing genetic syndromes. He measured 5 feet 11 inches and she said his previous pediatrician predicted he would reach least 6 feet 2 inches tall. Her child been diagnosed with multiple problems:

Genetics Is Not the Only Answer

Parents often suspect chromosomal anomalies and genetic syndromes when their children are born with multiple problems or congenital anomalies, especially if they include mental retardation and developmental delays.

It's Not Turner's Syndrome

In the case of this woman's son, the only real congenital anomaly was his horseshoe kidney, which is not that uncommon, occurring in about 1 in 500 children. And mitral valve prolapse is also very common, affecting about five to ten percent of people.

Those with a horseshoe kidney have one kidney that's fused together in a horseshoe shape, instead of two kidneys side by side, and a mitral valve prolapse is a heart condition.

Turner syndrome is a condition that can include all of her son's problems, including Grave's disease, mitral valve prolapse, scoliosis, and a horseshoe kidney. However, Turner's syndrome only affects girls.

It's Not Noonan Syndrome

Noonan Syndrome is a genetic disorder and occurs in approximately 1 in 1,000 to 2,500 children. It has similar symptoms, including:

  • scoliosis
  • heart defects
  • renal anomalies

However, these children also have mildly unusual facial features that her son didn't have, including:

  • a triangular-shaped face with a small lower jaw
  • wide-set, down-slanting eyes, usually pale blue or blue-green
  • short stature in 50 to 70 percent of patients

It's Not Chromosome 22q11.2 Deletions

Kids with chromosome 22q11.2 deletions can have many of the conditions the patient presented, including Graves' disease.

They do seem to have other findings, though, like cleft lip and palate and more serious heart defects, so this condition may not really fit.

It's Not Marfan Syndrome

A good pediatrician should also suspect Marfan syndrome in tall kids with heart murmurs and scoliosis. This genetic disorder affects the child's connective tissue, which holds all the body's cells and organs together and plays a critical role in helping your body grow.

However, Graves' disease is usually not a symptom.

How To Research Genetic Syndromes

When doing research, the National Organization of Rare Diseases can be helpful. Simply enter one or more symptoms or findings and see what diseases are commonly associated with them.

Jablonski's Multiple Congenital Anomaly/Mental Retardation (MCA/MR) Syndromes Database is another good resource. You can enter multiple congenital anomalies and see what conditions or syndromes match them.

The Rare Diseases site might also be helpful.

As you can see, diagnosing a genetic condition can be difficult. And it is not always as simple as ordering a chromosome test, to detect some genetic conditions requires more a detailed FISH analysis.

I suggested her son should have an evaluation by a Pediatric Genetics Specialist as the most helpful next step to see if there is a genetic condition linking her child's multiple problems.


The American Urological Association: What is Horseshoe Kidney (Renal Fusion)? (2015)

Genetics Home Reference: Noonan Syndrome (2011)

The Marfan Foundation: What is Marfan Syndrome?