|
Endemic Glaucoma in the Mune-Brgud Area (Endemski
glaukom u naseljima Mune i Brgud)
Aldo Valkovic, Ivana Valkovic-Antic and Asja
Valkovic-Mika
University Department of Ophthalmology, Rijeka University Hospital Center,
Rijeka, Croatia |
Summary
In the past century, research into the prevalence of congenital
glaucoma among the Mune and Brgud villagers showed that glaucoma was
present in 38% of the population. Genealogical studies established the
presence of congenital glaucoma through six generations of the
villagers. Tradition has it that members of the Sori family have
diseased eyes from time immemorial and that other families have
through generations been linked to this family in a repeated circle of
conjugal relationships.
From the considerable documentation collected, it appears that
approximately 50% of the population are genetically linked to the
central Sori family. In this group, about half of the offspring show
symptoms of this congenital disease.
Clinical characteristics of the Mune-Brgud congenital glaucoma are
similar to those of the late congenital glaucoma. It is caused by a
congenital anomaly of the iridocorneal angle, and is clinically
manifested between the age of 10 and 40. It is characterized by
goniodysgenesis and high insertion of the iris, remnants of
undifferentiated mesodermal embryonic tissue, widening of the
trabecular meshwork, decreased aqueous outflow, and regularly present
markedly deep anterior chamber. Megalocornea, hypoplasia of the
corneal stroma and moderate myopia are present sporadically. |
Sažetak
U prošlom stoljeću su istraživanja učestalosti kongenitalnog glaukoma
kod stanovnika naselja Mune i Brguda pokazala kako je glaukom bio
prisutan u 38% ove populacije. Genealoškim ispitivanjem utvrđeno je da
se prisutnost kongenitalnog glaukoma prati kroz šest naraštaja
stanovnika. Predaja govori kako su članovi obitelji Šori od davnina
imali bolesne oči te da su druge obitelji kroz naraštaje bile vezane
uz obitelj Šori kroz opetovani krug bračnih veza.
Iz obilne sakupljene dokumentacije proizlazi da je oko 50%
populacije ovih sela genetski vezano za središnju obitelj Šori. U toj
skupini prosječno polovica potomstva pokazuje simptome ove nasljedne
bolesti.
Kliničke značajke kongenitalnog glaukoma Mune-Brgud slične su onima
kod kasnog kongenitalnog glaukoma. Glaukom Mune-Brgud uzrokovan je
kongenitalnom anomalijom u iridokornealnom kutu i klinički se očituje
u dobi od 10. do 40. godine života. Obiljeažava ga goniodisgeneza i
visoka insercija šarenice, ostatak nediferenciranog embrijskog
mezodermalnog tkiva, prošireni trabekulum, smanjeno istjecanje sobne
vodice i redovito prisutna izrazito duboka prednja sobica.
Megalokornea, hipoplazija rožnične strome i umjerena miopija su
rijetko prisutne. |
Click image to enlarge
|
Fig. 1. The villages of Mune and
Brgud on the slopes of the Učka Mountain. |
The villages of Mune and Brgud are situated in the north Adriatic
region, on the slopes of the Učka Mountain (Fig.
1). In the past century, the research into the prevalence of congenital
glaucoma among villagers of the Mune and Brgud villages showed that
glaucoma was present in 38% of the population. Genealogical studies
established the presence of congenital glaucoma through six generations of
the Mune and Brgud villagers.
Generally, the anomaly that results in congenital glaucoma is
genetically determined and shows the recessive inheritance pattern in most
cases. This means that both parents are heterozygous and have a single
defective gene. Twenty-five percent of their offspring would be expected
to have two defective genes and thus to exhibit infantile glaucoma.
In the past generations, all Mune-Brgud family members had glaucoma,
and considering its clinical manifestation, the disease had a "dominant
character". Since it is a specifically structured clinical manifestation
in a geographically restricted population, the genetic material
accumulated (modifier) in the heterozygote to the homozygote with a very
high expression of the mutant gene where, through the evolution of
dominance, a new form of glaucoma developed, known as the Mune-Brgud type
of glaucoma1.
Genealogical studies report on typical family names of families with
glaucoma that recur in conjugal relationships through several generations.
These family names are Afrić, Ujcić, Hrvatin, Stenberger, Stambul,
Brentin, Gregoric and others, and experience confirms that a glaucomatous
disease can be seriously suspected in relation to the family name.
|
Fig. 2. A typical Mune - Brgud
rustic house. |
|
|
It has been reported that the Mune and Brgud villagers have a
traditional 200-year-old lifestyle and are strictly confined to their
villages. The elders have by common consent rejected the possibility of
the railroad passing through their village because it might disturb the
livestock, and to prevent strangers from coming to their village (Fig. 2).
The villagers lived a simple, modest and
neighbor-dependent life. They were mainly farmers and foresters, while the
eminent family nicknamed Sori that had 27 members 200 years ago, carried
on trade. Even today people talk about them. Their nickname could have
come from signori, Šiori in the dialect, meaning Italian
gentlefolk, which meant that they were the most significant and the most
distinguished family in the village, smarter and richer than others. They
were the first in the village and they made important decisions regarding
the community as the villiage elders.
Close relatives married each
other. To this day the people talk about them. Their nickname could have
elderly of the region say that it is better that the grandson marries a
girl from the family in order that everzone remains in the house, the
family stays united and the property preserved.
|
Fig. 3. Two of them are blind Mune
- Brgud villagers who never leave their villages. |
Tradition has it that members of the Šori family
have diseased eyes from time immemorial and that through generations other
families have been linked to this family in a repeated circle of conjugal
relationships, which is evident from the existing nicknames. Even today,
nicknames like Žvanetovi, Kušiljeri, Jurendovi, Starčovi, Vrklinari,
Barežinovi and Miminovi are interlinked and originate directly from the
Šori family. Close families welcomed marriages into the Šori family, which
dominated economically and had therefore attractive marital partners for
poor families.
From the considerable documentation collected, it appears that
approximately 50% of the population are genetically linked to the central
Šori family. In this group, about half of the offspring show symptoms of
this congenital disease. In some families, the prevalence of the disease
is even higher (Fig. 3). It is remarkable that other nicknames not
connected to the Šori family show no hereditary taint of the disease. The
first link of congenital glaucoma, which directly appears in the above
mentioned families of relatives linked by consanguineous marriages, is
thus accounted for2.
On the genealogical tree of the Afrić,
Stambul and Gregorić families, glaucoma is manifested in 80% of the 2nd
generation family members and in 75% of the 3rd generation
family members. In the 4th generation of subjects, the disease
has not appeared so far (Fig. 4). |
|
Fig. 4. Genealogical tree of the
Afrić, Stambul and Gregorić families. |
On the genealogical tree of the Afrić and
Brentini families, consanguinity is not observed in the 3rd
generation (Fig. 5). |
|
Fig. 5. Genealogical tree of the
Afrić and Brentini families. |
These deeply rooted characteristics,
established through a particular lifestyle and linked by consanguinity of
the villagers, disappeared for the most part after World War I and World
War II, and as the result of migration, mostly to the USA, which has only
reflected in the last two generations. Mixed marriages are no longer
taking place as the result of modern way of life and better
communications. This is the main reason why the manifestation of
congenital glaucoma in these villages has been decreasing, however, the
inheritance component of the disease is still observed depending on the
expression of the disease in the new marital relationships.
Clinical characteristics of the Mune-Brgud
congenital glaucoma are similar to those in the late congenital glaucoma
(glaucoma congenitum tardum)3. It is caused by
a congenital anomaly of the iridocorneal angle, and is clinically
manifested between the age of 10 and 40. It is characterized by
goniodysgenesis and high insertion of the iris, remnants of
undifferentiated mesodermal embryonic tissue, widening of the trabecular
meshwork, decreased aqueous outflow, and a regularly present markedly deep
anterior chamber. Megalocornea, hypoplasia of the corneal stroma, and
moderate myopia are present sporadically4
(Fig. 6).
|
Fig. 6. Widening of the
trabecular meshwork and markedly deep anterior chamber. |
|
|
Treatment is administered according to the
principles of treatment for congenital glaucoma. The method of choice is
antiglaucomatous filtering surgery5. In
clinical practice, we have observed that even when the disease is
medicamentously stabilized, sudden relapse may occur with elevated
intraocular pressure, quick development of glaucomatous cupping, and rapid
visual field deterioration leading to blindness, all in one year. For this
reason, almost all of our registered patients with glaucoma of the
Mune-Brgud type underwent surgery. Newly detected cases of glaucomatous
disease that either by inheritance or by characteristic family names or by
typical clinical manifestations pertain to the families from Mune and
Brgud are under intensive follow up 4 to 5 times a year. |
References:
- VESELINOVIC A. Nasljedni faktor u razvoju glaukoma.
Doctoral dissertation. Rijeka: Rijeka University School of Medicine,
1971.
- TAYLOR D. Pediatric ophthalmology. London: Blackwell
Science, 1997.
- KOLKER AE, HETHERINGTON J. Becker-Shaffes diagnosis
and therapy of the glaucomas. St. Louis, USA: CV Mosby Co., 1976.
- YANOFF M, FINE BS. Ocular pathology. Philadelphia,
USA: JB Lippincott Co., 1989.
- LEYDHECKER W Glaukom. Berlin, Heidelberg, New York:
Springer-Verlag, 1973.
Note:
Correspondence to: Aldo Valkovic, MD, University Department of
Ophthalmology, Rijeka University Hospital Center, Kresimirova 42, HR-51000
Rijeka, Croatia. Received January 30, 2007, accepted March 26, 2007
Source:
- Acta Clin Croat 2007; 46 (Suppl 1):
41-44,
Original scientific paper. © All rights reserved -
https://www.acta-clinica.kbsm.hr/arhiva/Acta2007/Acta1-supplement/008%20str%2041-44%20Valkovic.pdf
|
Main
Menu
Created: Thursday, November 01, 2007; Last updated:
Saturday, March 25, 2023
Copyright © 1998
IstriaNet.org, USA
|
|