MORTALITY FORUM 2013-04-30 Q2 Update 3

[mortality-forum]

MORTALITY FORUM 2013-04-30 Q2 Update 3

Question from Colin Fischbacher, Scotland

I'm looking for a code for Pallister-Hall syndrome and wondering
whether the code given by Orphanet is wrong.
Pallister-Hall syndrome is due to a mutation in the GLI3 gene and is
associated with extra fingers or toes, fusion of fingers or toes,
imperforate anus and other problems described here (http://
ghr.nlm.nih.gov/condition/pallister-hall-syndrome). A characteristic
feature of the condition is a hypothalamic hamartoma - a disorganised
overgrowth of normal tissue sometimes classified as a benign tumour. I
think this is the origin of the D33.0 code given by Orphanet. However
there is an ICD10 index entry for hamartoma that goes to Q85.9.
If the only or main feature of the disease was the hypothalamic
hamartoma I could see the case for Q85.9. However the range of
manifestations might suggest Q99.8 (other specified chromosomal
abnormalities). Would you agree that Orphanet's D33.0 is probably
wrong?
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From Colin Fischbacher, Scotland:

Thanks for the helpful clarifications. It sounds like Q87.8 would be
the best way to code the statement of "Pallister-Hall syndrome" if
there is no further information given on the certificate.

However I am still puzzled about the coding of "hamartoma" (though
this was not my original question). I think there is an ICD10 index
entry for "hamartoma" that goes to Q85.9 - is this wrong? Further, a
cancer registry colleague does not recognise hamartoma as a neoplasm
and says it is "a rare non-neoplastic heterotrophic lesion" (see
http://casereports.bmj.com/content/2013/bcr-2012-008273.long). I
therefore wonder about the basis for the D33.0 code for hamartoma -
where does this come from?

Many thanks again for all your helpful advice.

***********
From Donna Pickett and David Berglund, USA

It appears that Pallister-Hall syndrome affects multiple systems;
beyond those they mentioned, the kidneys are also often involved with
cystic malformations and also renal hypoplasia (see
http://www.ncbi.nlm.nih.gov/books/NBK1465/). The Online Mendelian
Inheritance in Man (OMIM) also describes a few other potential
problems it can cause, including heart defects and skeletal
abnormalities (http://omim.org/entry/146510; http://omim.org/clinicalSynopsis/146510).
Also, it is often lethal in neonates, although OMIM also notes that
hormone replacement is needed in long term survivors, so it is not
universally lethal. This is because the hypothalamus is missing,
replaced by the hamartoma. Apparently the presence of mesoaxial
polydactyly and hypothalamic hamartoma together can be enough to make
the diagnosis (based on the first reference above,
http://www.ncbi.nlm.nih.gov/books/NBK1465/), although it also notes
that suspected cases with polydactyly but without the hypothalamic
hamartoma can be considered for genetic testing.

Since it is a congenital malformation syndrome affecting multiple
systems, the best option for coding the syndrome in ICD-10 would be
code Q87.8, Other specified congenital malformation syndromes, not
elsewhere classified, as the underlying cause. If it were considered
desirable to separately code the hypothalamic hamartoma (or
hamartoblastoma), then it could be appropriate to consider the code
D33.0; Benign neoplasm of brain and other parts of central nervous
system; Brain, supratentorial. Other specific problems might also be
coded separately, as additional codes. Also, note that Pallister-Hall
is an autosomal dominant disorder involving mutation of a single gene,
and not a chromosomal disorder (which typically involve multiple genes
such as in a deletion or duplication), so codes from Q90-Q99 would not
be appropriate.

I do not think code Q85.9 would be applicable for this, as it is for
Phakomatosis, unspecified, even though that also includes Hamartosis
NOS. The phakomases are neurocutaneous disorders, including
neurofibromatosis and tuberous sclerosis, among other specific
disorders. I think those usually affect the skin more than Pallister-
Hall usually does, although OMIM does note that it can affect the skin
with midline facial capillary hemangioma.
***********
From From Luis Manuel Torres Palacios, Mexican Collaborating Center
for FIC (CEMECE)

Dear all

The Pallister-Hall syndrome must be coded as a genetic disease, maybe
in Q99.8 because there is not an specific code for this syndrome with
many congenital anomalies.
The Hamartoma or the hamartosis (overgrowths of normal tissue) are
common for some diseases like facomatosis and Pallister-Hall Syndrome.
Because the hamartosis is a characteristic feature for this and other
genetic syndromes, in the ICD-10 is coded in Q85.8.
We think you are right and D33.0 is wrong, because D33.0 is a code for
one of its manifestations but not for the Disease.