I am writing to ask if anyone can help my son Cameron. He has an unusual
metabolic disorder that has not been described before.
Cameron was born with no apparent problems on July 21, 1994. He was very
active and rolled over on his own ahead of schedule. He was also very
active visually and was fascinated with colors and intricate designs.
At about 2 ½ months, we noticed that his eyes were losing fusion. We
consulted opthamologists and began patching. Cameron's development began
to slow tremendously, and his doctors began to suspect that something else
was wrong. One doctor described him as not being aware of his
surroundings. His head growth rate also began to slow and fell well below
the bottom of the normal range. He appeared to be visually impaired, but
nothing could be found wrong in his visual system. Cameron had a lot of
tests (MRI, CAT, vision, hearing, chromosome, amino acid urinalysis/blood
analysis ) that all came back normal.
At age 24 months (7/96), the amino acid urinalysis was repeated and this
time came back abnormal. His histidine level was high and he was diagnosed
as having histidinuria. The amino acid blood levels were all still normal.
A spinal tap was performed a month later to check amino acids levels in
the CSF. Histidine and glutamine were both abnormally low (the glutamine
was at only 30% of the bottom of the normal range). Histidine was @ 6.0
(normal range is 9.6-15.8). Glutamine was @ 162 (normal range 498-583).
Right before his 26th month (8/96), we began supplementing his diet with 4
grams of glutamine per day . Approximately 2 weeks into the treatment, his
head growth spurted ahead to just under the bottom of the normal range. We
began adding 4 grams of histidine a few weeks later.
At 31 months (3/97), another spinal tap was performed. This time the
histidine was above normal and the glutamine levels had doubled, but were
still only 60% of the bottom of the normal range. Histidine @ 24.9,
Glutamine @ 322. Both of these amino acids were now high in his blood:
Histidine @ 222 (normal range 30-111), Glutamine @ 551 (normal range
238-520). We increased the glutamine to 8 grams/day and dropped the
histidine down to 2 grams/day almost 4 weeks ago. Since then, there has
been little change noticed.
Since the diet changes, his development rate seems to have increased,
though he is still not developing at a normal rate. All of his development
milestones have been late to differing degrees. His speech is extremely
delayed -- at 32 months of age, he is not even close to saying a word.
His vision is still impaired and his eyes still have problems fusing. His
head size is still below normal, but at least seems now to be growing at
the normal rate. He is in speech and physical therapy, and they are
pleased with his progress since beginning the diet changes. His emotional
development seems to be ahead of his other areas. He also likes to stare
at light sources and, oddly, newsprint.
Do you know what could be causing the abnormally low levels of these amino
acids in the CSF? There is no family history of any amino acid
abnormalities. Why are the glutamine levels normal in the blood and urine,
but very low in the CSF? Do you know of other ways to safely raise the
glutamine in his brain? Can you explain the vision and speech problems?
Have you ever encountered anything like this?
Any input you can provide will be greatly appreciated.
