The Full Trisomy 8
The full trisomy for chromosome 8 has been established clinically 
and the first demonstration by chromatid fine structure analysis was given by
de Grouchy et al. .
Recently we have reviewed 5 cases of 8-trisomy, all of them identified
in our laboratory by heat controlled denaturation .
The full syndrome, exemplified in fig. 1, can be summarised as a
general dysmorphy of the bones including koilosterny and 13 ribs, abnormalities
of vertebrae and of iliac bones, brachymesophalangy, syndactyly and club foot
with limitation of movements of most of the joints.
In contrast, the head is macrocephalic with a eumorphic face. On the
ears there is an irregular helix and an excess of the anthelix is seen. The
mental deficiency is marked but probably less profound than in 21 trisomy.
The dermatoglyphics shows an upward direction of distal flexion
crease, ending between the second and the third digits and all the creases are
deep, with little dimples giving an "aspect capitonné". The axial triradius is
elevated, the ridges of the distal part of the palm have a cubital orientation
(low index of transversality) and there is an excess of arches.
The new trisomy syndrome is thus clinically easily recognized and can
be diagnosed firmly by mere inspection and secondarily confirmed by the
Trisomy for Distal Part of Long Arm of Chromosome
The particular syndrome was first described in two brothers, mildly
mentally retarded. Both of them had 47 chromosomes, the extra one being roughly
of the size of a G.
According to the old techniques, both parents exhibited a normal
karyotype. With denaturation, the mother showed a dark segment on the end of
the long arm of No. 8 and one of her No. 22 was replaced by an acrocentric, the
long arms of which were rather pale. Hence this small acrocentric consisted of
the end part of long arm of No. 8 translocated on the centromere of 22. The
long arm of 22 was found at the end of the rearranged 8.
The two boys were trisomics for the distal part of chromosome 8
A very similar translocation was found recently by Dr Prieur in
another family, apparently unrelated, in which a boy (fig. 2) had 47
chromosomes with the same extra pseudo-G, and the father had the 22-8 balanced
translocation (fig. 4C).
From these 3 cases we can describe the disease as a mildly dysmorphic
syndrome affecting the sternum, the vertebrae, the iliac bones, the digits and
the toes as in trisomy 8 but to a milder extent and with no involvement of the
articulation and with normal ribs. Two of the boys were operated for ectopic
The head is also macrocephalic and the mental retardation is mild (IQ
in the order of 70). Dermatoglyphics shows normal creases but an elevated end
of the distal flexion crease and elevation of the axial triradius.
Trisomy for Short Arm and Middle Part of Long Arm of No.
In one case, analysed by Dr Rethoré, we have observed 47 chromosomes,
with the extra element being recognized as a No. 8 lacking the terminal part of
its long arm (fig. 4B).
This young girl is microcephalic with hypertelorism and has a large
broad nose. She has 13 ribs, abnormality of the twelfth vertebra and of the
sacrum, and narrowed iliac bones. There is limitation of joint mobility and a
club foot (fig. 3).
The creases are 'capitonnés' on the feet but normal on the hands. The
ridges of the palms have a cubital orientation (low index of
It is obviously impossible to designate a new entity based on only one
case, but apparently this girl exhibits some of the stigmata of trisomy 8 and,
precisely, those which are not found in the trisomy for the end of the long
arm. With the increasing amount of similar data, it seems possible that mapping
of the phenotypic effects of various chromosomal segments may commence in the
Fig. 1. Trisomy 8. Fig. 2. Trisomy for
the distal part of long arm of chromosome 8 (trisomy 8q ter). Fig. 3. Trisomy
for the short arm and the proximal part of long arm of chromosome 8 (trisomy 8q
Fig. 4. (A) Full
trisomy 8 ; (B) Trisomy 8q- ; (C) Trisomy 8q ter by 22-8 translocation
|Full trisomy No. 8||Trisomy for the end part
of long arm of No. 8||Trisomy for short arm and proximal part of long
arm of No. 8
|Deep creases "plis
|Distal crease ending in 11||+||+||-
|Elevated axial triradius||+||+||-
|Low index of
|Excess of arches||+||-||+
It has proved to be very useful for clinical doctors to have a
common name for a syndrome, such as "cri du chat" syndrome. Could you propose
common names for trisomy 8, and the partial trisomy 8-syndromes?
Unfortunately not. To propose a useful name we need a main symptom
which is quite pathognomonic. Maybe with an accumulation of new cases the
clinical picture will clarify sufficiently to permit such a representative
Your finding of creases in the hands and feet is of interest in
relation to the report by Penrose of specific dermatoglyphic features in one
subject with trisomy 8. Do you have any information on the dermatoglyphic
pattern in your cases with different abnormalities of chromosome 8?
Yes, and they are quite typical in each syndrome:
Trisomy 8 (full chromosome): Axial triradius elevated. Low index of
transversality of ridges. "plis capitonnés", with the distal flexion crease
ending betwen II and III (deeply engraved palmar creases); brachymesophalangy
and symphalangy arches on fingers.
Trisomy 8q terminal (trisomy for the end portion of the long arm of
No. 8): Axial triradius elevated; distal flexion crease ending between II and
III; brachymesophalangy; index of transversality normal; no "plis
Trisomy 8 q (trisomy for short arm, centromere and two-thirds of
long arm of No. 8): Index of transversality very low; "plis capitonnés";
excess of arches.
1. Lejeune, J, Dutrillaux, B, Rethoré, M-O, Berger, R, Debray, H,
Veron, P, Gorce, F & Grossiord, A, Ann génét 12 (1969) 28.
2. de Grouchy, J, Turleau, C & Leonard, C, Ann génét 14 (1971)
3. Dutrillaux, B & Lejeune, J, Compt rend acad sci 272 (1971)
4. Lejeune, J, Rethoré, M-O, Dutrillaux, B & Martin, G, Exptl
cell res 74 (1972) 293.