Fróðskaparrit - 01.01.1969, Blaðsíða 18

26 Intermittent Intrahepatia Cholestasis of Unknown Etiology
Australia12. Some episodes in patients from the present series
have started during a stay in Denmark. Dietary and other
environmental toxic agents therefore are less likely. An aller-
gic reaction has been suspected in some patients who had other
allergic manifestations, e. g. case 2 of the present series and
case 2 of Kiihn^, but no relation between these manifestations
and the episodes of jaundice has been demonstrated, and in
the majority of patients no symptoms or signs of allergy were
found. In one patient7 ohlorpromazine and norethandrolone
did not provoke jaundice, and in the present series chlor-
promazine has been used as a sedative on several occasions
without illeffects.
Thus by exclusion a metabolic defect may be incriminated.
It is not certain whether the syndrome is heriditary. Among
the 24 unquestionable cases 6 occur in three families2 4 14 and
the further six probable cases are relatives of certain cases1011
14, present series.
The relatively high incidence of the syndrome at the Faroe
Islands (five patients among 37.000 inhabitants) conform with
the hypothesis of a heriditary defect, since this community is
relatively isolated with a high proportion of intermarriage.
It has been suggested that the mode of inheritance is by way
of a sex-linked recessive14, but the observations are too in-
complete to confirm this. The pedigrees of the probands in the
present series have been followed as far as possible without
revealing further cases or further links between the families
of known cases. In general the families are large at the islands
and the oontemporary members know each other well, but in
most cases only two or three generations can be traced back.
It must be concluded that if the syndrome is heriditary, the
dominance of the defect must be very weak.
The hepatic uptake and conjugation of bilirubin is con-
sidered to be normal6. Direct reacting bilirubin was found to
contribute from less than 50 per cent4 8 10 22 to about 80 per
cent11 of total bilirubin. In the patients of the present series
unconjugated bilirubin was normal or lower than normal, in