B. Brandsaberi et al., DISTRIBUTION OF EXTRACELLULAR-MATRIX COMPONENTS IN NUCHAL SKIN FROM FETUSES CARRYING TRISOMY-18 AND TRISOMY-21, Cell and tissue research, 277(3), 1994, pp. 465-475
We have investigated histologically the elevations of the skin in dors
al and lateral neck (nuchal) regions of human fetuses carrying karyoty
pes of trisomy 18 (Edwards' syndrome) and trisomy 21 (Down's syndrome)
. Cavities filled with interstitial fluid were found in the dermis, ep
idermal basement membrane and occasionally in the epidermis of trisomy
-18 fetuses, but were not delineated by an epithelium or basement memb
rane as judged by the absence of immunostaining for laminin, collagen
IV and collagen VII. Dilated vessels were also found al the interface
between dermis and subcutis. Neither normal fetal skin nor that of tri
somy-21 fetuses contained cavities or dilated vessels. In order to det
ect possible alterations of the extracellular matrix in trisomy-18 and
trisomy-21 skin, the distribution of glycoproteins, glycosaminoglycan
s and proteoglycans was studied immunohistochemically. In trisomy-21 a
nd control skin, the dermis stained intensely for fibronectin, whereas
the subcutis reacted only weakly. In trisomy-18 skin, the stronger st
aining for fibronectin appeared in the subcutis, and the prevailing co
llagen type was collagen III, collagen type I being absent. In the ski
n of trisomy-21 fetuses, collagen VI was more irregularly arranged and
densely packed, whereas collagen I was more widely spaced than in nor
mal fetuses. More hyaluronan was present in the dermis and subcutis of
trisomy-21 fetuses than in that of trisomy-18 and control fetuses. A
correlation seems to exist between undelimited cavities and collagen I
II in trisomy-18 skin, and between hyaluronan and the specific arrange
ment of collagen in trisomy-21 skin.