Hello everyone,
is there a substantive reason why the same diagnosis has two SCTIDs:
SCTID: 66937008 Amylo-1,6-glucosidase deficiency
SCTID: 124472001 Deficiency of amylo-1,6-glucosidase
Thank you in advance for the clarification.
Hi!
The first one has a different Fully Specified Name:
66937008 |Glycogen storage disease, type III (disorder)|
This concept represents the clinical syndrome.
The second one represents the actual deficiency underlying the syndrome:
124472001 |Deficiency of amylo-1,6-glucosidase (disorder)|
These are closely related but distinct; one may be more useful than the other in particular contexts.
Having the synonym “Amylo-1,6-glucosidase deficiency” in the “Glycogen storage disease, type III (disorder)” concept may require further consideration; it was added in 2017, years after the concept was created, likely in response to user requirements.
Best regards
Alejandro
Yes, this is one of many examples of medical “etiological naming” conventions, wherein a broad (and often variably expressed) downstream phenotype is given the same name as the fixed upstream pathology that ultimately causes it. In this case, a syndrome phenotype carries the same name as the biochemical error that fundamentally causes it. There are MANY other examples, especially now in genetics.
Much older examples include “malaria”, which was originally (but mistakenly) named for the “mal (bad) air” that was believed to cause it. More modern pre-genomix examples include heavy metal poisonings, a host of forms of fibrosing alveolitis that are named primarily for their causative agent (Silicosis, Ornithosis etc) and many biochemical states, including of course “hypoglycaemia”.
There are some heritable inborn errors of metabolism that cause one distinct phenotype when they occur in isolation, but a different one when they co-occur with another inborn error. HbS, beta-thalassemia and HbS with beta-thalassemia are perhaps the best known such triad. But this example explains why, for ontological consistency, it is necessary for all biochemical errors (such as amylo-1,6-glucosidase deficiency) to be represented separately in SNOMED from the phenotypes that they cause, even when both are by convention often given the same label.
This was one of the primary reasons for the addition of the new attribute HAS DEFICIENCY OF, which allows the syndrome caused by the deficiency to have the an explicit releation back to the deficiency itself. Having this new attribute, plus the addition of more specific naming conventions for the FSN will make the distinction between the cause and effect more visible.
Really?
If 66937008 is ‘…the syndrome caused by the deficiency…’ and 124472001 is ‘…the deficiency itself…’ then this quote suggests HAS DEFICIENCY OF will related the former to the latter.
However in all briefing notes and discussions I can find we are told that HAS DEFICIENCY OF will take substances in its range. I would therefore expect HAS DEFICIENCY OF to be used to define 124472001 |Deficiency of amylo-1,6-glucosidase (disorder)| in terms of 45947007 | Amylo-1,6-glucosidase (substance) |.
Surely it will be DUE TO relationships (Indicative proposal 4a “Define 410053003 |Clinical manifestation of enzyme deficiency (disorder)| as a 75934005 |Metabolic disease (disorder)|DUE TO 129456006 |Specific enzyme deficiency (disorder)|”) that will relate the two disorder/finding classes?
More generally - and for the record - I still think the ‘ontologically pure’ distinction SI/EAG are attempting to represent here introduces very practical usability and understandability risks that have not yet been addressed.
Your interpretation of the modeling is correct. My apologies for the misunderstanding