Congenital hypothyroidism in a Turkish family: the role of immunoglobulins blocking the trophic effects of TSH and maternal-foetal relationship.
A Turkish family with frequent intermarriages is described, in which two siblings were born with persistent forms of congenital hypothyroidism, in the elder child concomitant with absent radioactive thyroid imaging. The mother was clinically euthyroid throughout the period of observation, but showed in addition to thyroid microsomal antibodies, high levels of immunoglobulins blocking the trophic action of TSH. These maternal growth blocking antibodies were transiently present in the youngest of the siblings (from birth to 2 months of age). She had a relatively mild form of congenital hypothyroidism (T3: 33 micrograms/100 ml; T4: 3.9 micrograms/100 ml). The older sibling, with proven non-functioning thyroid tissue (negative thyroidscan, T4: 0.4 microgram/100 ml) produced the growth-blocking immunoglobulins herself and may thus represent a juvenile form of thyroid autoimmunity with a very early onset. An aunt and uncle of the children, both hypothyroid since birth, were at the age of 19 and 18 years weakly positive for growth blocking immunoglobulins. This study indicates that familial forms of congenital hypothyroidism are probably complex and may be brought about by maternal to foetal passage of thyroid reactive autoantibodies, but also by the inheritance of a trait for thyroid autoimmunity. In some cases these two mechanisms might act in conjunction.
van der Gaag
R D
RD
Frisch
H
H
Weissel
M
M
Wick
G
G
Drexhage
H A
HA
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000032:analysis*; D002648:Child; D003409:Congenital Hypothyroidism; D003241:Consanguinity; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000235:genetics / Q000276:immunology; D007074:Immunoglobulin G / Q000032:analysis*; D018828:Immunoglobulins, Thyroid-Stimulating; D008297:Male; D008431:Maternal-Fetal Exchange; D010375:Pedigree; D011247:Pregnancy; D011956:Receptors, Cell Surface / Q000276:immunology*; D011989:Receptors, Thyrotropin; D013961:Thyroid Gland / Q000276:immunology; D014421:Turkey / Q000208:ethnology
D001323:Autoantibodies; D007074:Immunoglobulin G; D018828:Immunoglobulins, Thyroid-Stimulating; D011956:Receptors, Cell Surface; D011989:Receptors, Thyrotropin