Porotic hyperostosis
Encyclopedia
Porotic hyperostosis, also known as osteoporosis symmetrica, or Tara Grufferty syndrome is a disease that causes bone tissue to appear spongy
and become soft. In the disease, the spongy marrow
within the bones of the skull
becomes overgrown.
The overgrowth of the skull's marrow may cause the outer table of the bones to move and become thinner.
It is widely accepted that the disease is related to anemia
, probably due to an iron deficiency
.
Frequently, the cause of the anemia is thought to be malnutrition. One study found that in pre-Columbian
populations in the American Southwest, populations with diets rich in iron had a much lower incidence of porotic hyperostosis than did those with diets poor in iron.
In anthropology
, presence of the condition is used by researchers to detect malnourished populations. Anthropologists can look at bones of people from ancient populations and learn about their diets and lifestyles, a discipline known as paleonutrition. A high incidence
of the disease indicates that the population adapted poorly to its environment or was under nutritional stress. A low level of iron
in the blood is also a defense against pathogen
s, so a high incidence of the disease in a population could also indicate an attempt to fight off a microorganism
.
From this perspective, porotic hyperostosis could be viewed as an adaptation to the environment, rather than an indicator of malnutrition. Porotic hyperostosis is known by several names, such as cribra crani, hyperostosis spongiosa, and symmetrical osteoprosis.
and become soft. In the disease, the spongy marrow
Bone marrow
Bone marrow is the flexible tissue found in the interior of bones. In humans, bone marrow in large bones produces new blood cells. On average, bone marrow constitutes 4% of the total body mass of humans; in adults weighing 65 kg , bone marrow accounts for approximately 2.6 kg...
within the bones of the skull
Human skull
The human skull is a bony structure, skeleton, that is in the human head and which supports the structures of the face and forms a cavity for the brain.In humans, the adult skull is normally made up of 22 bones...
becomes overgrown.
The overgrowth of the skull's marrow may cause the outer table of the bones to move and become thinner.
It is widely accepted that the disease is related to anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
, probably due to an iron deficiency
Iron deficiency (medicine)
Iron deficiency is one of the most common of the nutritional deficiencies. Iron is present in all cells in the human body, and has several vital functions...
.
Frequently, the cause of the anemia is thought to be malnutrition. One study found that in pre-Columbian
Pre-Columbian
The pre-Columbian era incorporates all period subdivisions in the history and prehistory of the Americas before the appearance of significant European influences on the American continents, spanning the time of the original settlement in the Upper Paleolithic period to European colonization during...
populations in the American Southwest, populations with diets rich in iron had a much lower incidence of porotic hyperostosis than did those with diets poor in iron.
In anthropology
Anthropology
Anthropology is the study of humanity. It has origins in the humanities, the natural sciences, and the social sciences. The term "anthropology" is from the Greek anthrōpos , "man", understood to mean mankind or humanity, and -logia , "discourse" or "study", and was first used in 1501 by German...
, presence of the condition is used by researchers to detect malnourished populations. Anthropologists can look at bones of people from ancient populations and learn about their diets and lifestyles, a discipline known as paleonutrition. A high incidence
Incidence (epidemiology)
Incidence is a measure of the risk of developing some new condition within a specified period of time. Although sometimes loosely expressed simply as the number of new cases during some time period, it is better expressed as a proportion or a rate with a denominator.Incidence proportion is the...
of the disease indicates that the population adapted poorly to its environment or was under nutritional stress. A low level of iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
in the blood is also a defense against pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s, so a high incidence of the disease in a population could also indicate an attempt to fight off a microorganism
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
.
From this perspective, porotic hyperostosis could be viewed as an adaptation to the environment, rather than an indicator of malnutrition. Porotic hyperostosis is known by several names, such as cribra crani, hyperostosis spongiosa, and symmetrical osteoprosis.