Dear Rita:
I was very interested in your e-mail regarding glactosemia and
glactoskinanse deficiency.
I found a more current reference: The Metobolic and Molecular Bases
of Inherited Disease, volume 1, seventh edition, 1995 - authors :
Schiver, Beaudet, Sly and Valle.
Chapter 25 beginning on page 967 talks in detail about disorders of
galactose metabolism, the authors of this chapter are: Staton Segal
and Gerard T. Berry.
To answer the questions:
Q - Is a deficiency of glactokinase also considered galactosemia,
or is that term reserved for deficiency of galactose 1-phosphate
uridyl transferrase?
A - Yes, glactokinase deficiency is considered to be a form of
galactosemia. In reading this chapter and discussing this with
sources at our department of health, this type of glactosemia is
even more rare than the galactose 1-phosphate uridyl transferrase.
And because of it's rarity, our state lab does not routinely screen
for this on that first test.
According to this book, there are three types of
galactose metobolism disorders, galactokinase deficiency, galctose
1-phosphate transferrase and uridine diphosphate galactose
4-epimerase.
Q - Are there degrees of disease, or are these deficiencies all or
nothing?
A - Various levels of toxicity result from exposure to
glactose.
The book states that: " Toxicity in glactoskinase
deficiency is milder and is mainly manifested as cateracts. In
transferrase and generalized epimerase deficiency, galactose
ingestion is characterized by inanition, failure to thrive, vomiting,
liver disease, cateracts, and developmental delays."
I couldn't say that there are degrees of the disease but it appears
there is some variation from time of onset of syptoms. The books
also states that these symptoms disappear when galactose is removed
from the diet.
From my discussion with the haelth department, the scary thing about
this disease is that although it can progress slowly, it can also
progress with great speed and there is really no way to tell which
baby will progress slowly with the disease process.
It would be best if she sat down with her physician and tried to sort
out what exactly she is dealing with.
Questions I might pose to that mother: Is there a family history
of this disease? If so, what was the outcome for that family member?
If the mother decides to continue breastfeeding, what exactly should
she be looking for in terms of symptoms and most importantly will the
physician support her decision to continue nursing and be ready to
deal with the consequences if symptoms occur?
Informed consent and current information are two critical pieces
here.
The book talks about cataracts being one of the first symptoms of
galactokinase deficiency. It states that this may be detected only
by slit-lamp examination by an ophthalmologist. Diagnosis of
cateracts is "missed with an ophthsalmoscope, since they consist of
punctate lesions in the fetal lens nucleus".
The other thing to be aware of is that even though the book talks
about this being a milder form of galactosemia it elaborates about
other symptoms besides catereacts so I would be cautious about
recommending the continuation of breastfeeding.
Q - How common are false positives for any of these tests?
A - The state labs keep records of that and it would be a matter of
calling your state lab and finding out.
My interest in this topic was peaked after the birth of my fourth
child. Two weeks after his birth I received a call from my
pediatrician regarding the test result of his screen. Before he
could even say the word galactosemia, I said it to him - and he
asked me how I knew about it.
I have two first cousins that have galactosemia. Much of the early
research was done in Chicago and involved my cousins. They were
lucky as it was caught early and they had minimal problems. That was
in the late 1940's amd early 1950's.
Anyway, my physician wanted to see my baby right away. I was
terribly shaken by the news. The thought of not being able to nurse
my baby was devastating to me. My doctor examined my baby and had
the lab tests run again. He sent the tests to both the state lab and
an independent lab and oversaw that proper procedure was followed.
He felt it was safe for me to continue to breastfeed since my son was
not exhibiting any symptoms. I too felt a sense of panic and urgency
in trying to gather more information about the topic from which to
make an informed choice. They was a definite void of information in
the literature available to me. In looking back over the situation
and now understanding that lack of symptoms does not mean lack of
disease I might have done things a bit differently.
As it turned out my son had a false positive result on his test the
first time and a negative result the second time from both labs. The
first blood draw was done on an extremely hot day and was most likely
handled improperly.
According to my health department source, if the test is exposed to a
heat source it will kill the enzyme activity. Thus producing a false
positive test reslut. Another source of false positives are the
result of "rushing the test" by not allowing it to dry throughly
before it is placed in the mailing envelope.
Our story had a happy ending but I think we need to be cautious about
how we give information about this topic.
Q - How much damage would continuing to nurse for a week cause if
there is a deficiency in galactokinase, and what kind of damage could
be expected?
A - I don't think any one could answer this with absolute
certainty. The possiblity exists that there would be no permanent
damage. But the mother would need to way the risks vs. benefits
of continuing breastfeeding .
Q - Lawrence and Auerbach & Riordan say "the baby will soon develop
symptoms." How soon is soon? Days? Weeks? What kind of symptoms?
A - That is the variable from baby to baby. I described the
symptoms above. As for the time frame - you may see symptoms within
a few days of birth to several weeks or months later.
Another resource you may find helpful is Julie Stock from LLLI. I
talked with her about my situation in 1990 and she told me about the
possiblity of mishandling of the test specimen.
I hope I have given you some information that may be helpful to this
mother as she makes a choice about what to do .
Joanne M. Wesley
IBCLC
|
