Do I get a second opinion?

[Kovash]

My son just turned 6 and is 41 inches and weighs 35 pounds.  He was refered to a ped. endo.  We had the appointment and had some blood tests done that show his IGF-1 to be low.  It is at 32 and I was told that normal is between 60 and 228 at his age.  He has also had a bone age done and it showed 4 years & 4 months of age.  We have a GH stim test scheduled and will probably do that.  I don't know if that 32 IGF-1 is a little low or if it significantly low.   I guess I am wondering if it would be a good idea to get a second opinion.
Thanks.

[Becmn]

A related discussion, Further testing needed? was started.

[Deanna L Aftab Guy, MD]

With your height and dad's the midparental height for your son and all of your sons is around the 50th percentile or about 5'10 inches, now 2 full standard deviations either way is 4 inches so this means that at the 10th percentile is 5'6 and that is the shortest genetic variation that is acceptable. Your child is below the 3rd and you are describing some developmental problems. I would stick with your peds endo, eventually once they establish a growth velocity, by seeing him in their office and plotting measurements they will make a decision about gh stim testing or other testing, like imaging or metabolic testing that can relate to develomental delays.
Yes, if you have history of pubertal delay this is still taken into account but at this time not something I am considering, I am more suspicious of his growth given he was on the chart as an infant and decelerated, I am sure your peds endo agrees but also knows that we have time to make up our minds about treatment path. Hang in there,stay with them and go at least every 4-6 months for remeasurements and assessments.
Glad to hear that thyroid and celiac were normal but if they were a little off if it were me I would be repeating it at another visit-but that's me

[Kovash]

Thank you for your reply.  To answer your questions, he was tested at one time for celiac and did have his thyroid tested.  The celiac test was normal and the thyroid was essentially normal I was told.  I don't know numbers.  I was told that there was a slightly "off" number but the ped. endo. told me that it was not a big deal.  I wish I knew that number so I could relate it here.  His birth weight was 6lbs 12oz and he was 18 1/2 inches.  He was born 18 days early, and was healthy and had no problems after birth.  He grew at a pretty steady pace and was actually quite chubby for a baby until about 10 months of age when he drastically slowed down.  And regressed developmentally in some areas.  He has continued to be delayed developmentally in some areas and congnitively average.  He has sensory intrigration disorder and verbal apraxia.  He also has a handful of allergies to the environment and foods and also has reactive airway.  I throw all those out ther because I'm not sure if those would play into any diagonsis.  He is number 4 of 5 children.  The ages and sizes of those children are; 9.8 year old girl, 52" and 57 lbs; 7.9 year old boy, 49 1/4" and 50 lbs; 3.6 year old girl, 38" and 32 lbs; 5 month old boy, 25 1/2" and 16lbs.  My husband is 5'11" and 165lbs and I am 5'4" and 135lbs.  My husband was not a late bloomer (I was told that the same sex parent can indicate timing for puberty in children).  I (his mother) was a little late.  I started developing at around age 12 but did not start my period till I was 15.  Do you take the opposite sex parents development into play with that?

[Kovash]

Thank you for your reply.  To answer your questions, he was tested at one time for celiac and did have his thyroid tested.  The celiac test was normal and the thyroid was essentially normal I was told.  I don't know numbers.  I was told that there was a slightly "off" number but the ped. endo. told me that it was not a big deal.  I wish I knew that number so I could relate it here.  His birth weight was 6lbs 12oz and he was 18 1/2 inches.  He was born 18 days early, and was healthy and had no problems after birth.  He grew at a pretty steady pace and was actually quite chubby for a baby until about 10 months of age when he drastically slowed down.  And regressed developmentally in some areas.  He has continued to be delayed developmentally in some areas and congnitively average.  He has sensory intrigration disorder and verbal apraxia.  He also has a handful of allergies to the environment and foods and also has reactive airway.  I throw all those out ther because I'm not sure if those would play into any diagonsis.  He is number 4 of 5 children.  The ages and sizes of those children are; 9.8 year old girl, 52" and 57 lbs; 7.9 year old boy, 49 1/4" and 50 lbs; 3.6 year old girl, 38" and 32 lbs; 5 month old boy, 25 1/2" and 16lbs.  My husband is 5'11" and 165lbs and I am 5'4" and 135lbs.  My husband was not a late bloomer (I was told that the same sex parent can indicate timing for puberty in children).  I (his mother) was a little late.  I started developing at around age 12 but did not start my period till I was 15.  Do you take the opposite sex parents development into play with that?

[Deanna L Aftab Guy, MD]

You are describing a 6 year old boy with weight just under the 3rd percentile and height more than that below the 3rd percentile.
His igf-1 is low for age but normal for his bones, meaning he could still have growth hormone deficiency but it also may still be late bloomer and the difference can only be decided by time and a gh stim test.
Differential diagnosis for short stature includes central (those from the pituitary) causes such as possible but rare central lesion of the brain, isolated gh deficiency, constitutional delay(term used for late bloomer), gh resistance, igf-1 deficiency, other endocrine disorders such as adrenal insufficiency, thyroid disorder, nutritional disorders such as celiac disease or malabsorptive process, other chronic disorders that would prevent growth such as rheumatoid arthritis or other inflammatory problems, hematological disorders, chromosomal abnormalities such as Noonan's or Kallman's in the boys  or Turner's syndrome in the girls.
Workup includes bone age-which they did, labs that include chromosomal (probably not needed in a 6 yo boy right now) and hematological (blood count) as well as metabolic indices, imaging studies such as mri of the pituitary with and without contrast and ultimately deciding about gh stimulation testing.
As growth hormone is not easily measured or interpreted at random sampling periods-cause it is made at night in drips like a faucet, catching the level is hard without frequent intermittent testing-so we do a test called the gh stim test which is like fishing for growth hormone, we give the child two medications each one at a time to double check the body's response- this testing is done to stimulate it's production and measure the peak growth hormone level. This includes using medications that help diminish the inhibitors of growth hormone or stimulate it, insulin is one of these medications as it allows for the blood glucose to drop some and growth hormone being a counterregulatory hormone is usually secreted in response to this. Also Arginine, an amino acid helps stimulate growth hormone via another mechanism. These two are often used one after the other in a stimulation test in order to see a patient's ability to secrete growth hormone. Desired levels are compared to the patient's response and interpreted.
Tell me about his past history-what was his birth weight and age of gestation-preterm versus term? Did he have any medical history prior to this? Did they test celiac panel and thyroid?