Rare Genetic Blood Disorder Thalassaemia Cluster in Sardinia, Italy

Sardinia is a beautiful Italian island, with a rich culinary history and its own unique language ecosystem (Sardinian, Sassarese, Gallurese, Algherese Catalan, Ligurian) (Shutterstock):

shutterstocksardinia

A while ago, I started a separate awareness website called Rare K. Each week, a different rare disease would be highlighted. This week, I brought attention to thalassemia, a rare blood disorder (genetic). Patients born with beta-thalessemia have less oxygen-carrying protein in their blood -- hemoglobin. Without lifelong treatment, obvious complications arising can kill before age 30. Today, one of my Instagram followers -- also a chef, and also a rare disease patient (a carrier, specifically) -- reached out to me with a very interesting piece of information: in his hometown, there is a high incidence of this conditon. 19.5% is very high for a specific illness that typically affects just 0.06% of the human population typically.

It occurs to me I've also been reached out to in the past by a follower (morphea patient in Spain); the rare atrophic cutanous condition runs in her family with an extremely high occurrence rate. This is not to say there is a clear genetic or environmental component (although research indicates both may contribute in some unbeknownst way to the expression of the disease) to these specific rare diseases or all rare diseases. It is just interesting to note.

Excerpt from the NIH study, where samples were drawn in a longitudinal study of the population:

blooddata

State-sponsored genetic testing of an entire isolated population is not a new idea. I remember first being exposed to the idea watching a Netflix documentary (I forgot the name now). I think it was in regard to the Faroe Islands (North Atlantic), where carnitine transporter deficiency (CTD) among other rare diseases present higher-than-average incidence rates. Sweden and Finland appear to have some systems in place as well.

On the Faroe Islands, people still practice some ancestral food traditions, like whaling and foraging for fulmar eggs on steep cliffsides. It's also important to remember relative isolation should not lead us as scientists to assume an increase in rate of rare disease or disease in general. We often misunderstand the idea of genetic mutation and instantly think of the blue-skinned Fugate family of Kentucky. Over generations, we may see enrichment in some genetic variants and losses in others. Nevertheless, the potential of accessible genomic testing, as well as advancements in IVF, PVG, PGS, and CRISPR, for certain medium-high risk populations is promising when we think about eliminating rare diseases with a possible genetic component (moral/ethical implications aside for now).

Methemoglobinemia, a rare condition caused by elevated levels of methemoglobin (a type of Fe^3+ iron cation containing hemoglobin), causes the characteristic blue skin color associated with the Fugate family of Troublesome Creek. It has become associated in popular culture with intermarriage; as with other blood disorders with a congenital factor, if two parents happen to be carriers of the (in this case recessive met-H) trait, it can be expressed in their offspring with a certain likelihood. 

kentuckyblues

Hemophilia is another rare blood disorder involving clotting difficulty due to genetic deficiency of clotting factor VIII. It can be inherited as an X-linked recessive trait or arise from a number of spontaneous mutations. The condition has long been surrounded in stereotype/urban legend/conspiracy theory, most notably regarding its ties to the royal family:

queenvictoria

It's important to note while we may yet find some interesting clusterings of rare diseases/other findings indicative of some genetic pathway for diseases, there are many factors involved in the expression of disease. What's more expression of disease is in NO way the fault of a patient. Inherited/heritable disease is especially NOT the fault of a child who is born with a potentially devestating illness. As scientists, we are NOT here to formulate socio-judgements but to explore possible ways to help.

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