Partial trisomy 9q: A new syndrome

Abstract

Two unrelated patients with a strikingly similar phenotype (low birth weight and poor thriving; mental retardation; dolichocephaly; beaked nose; deeply set eyes; prominent maxilla and receding small chin; long fingers with a peculiar clench) were partially trisomic for two different segments of 9q. The segment found to be trisomic in both patients is small and corresponds to the q31q32 region. This new syndrome is compared to observations of trisomy 9 reported in the literature.

Identification of an unbalanced cryptic translocation t(9;17)(q34.3;p13.3) in a child with dysmorphic features

“…Moreover, all of the published cases were unbalanced products of parental translocations involving a variety of segmental monosomies with the exception of a family reported by Allderdice et al 17 An insertion of chromosome 9 resulted in seven recombinant family members with duplication of band 9q34. This report 18 19 20 21 22 22 22 17 17 17 17 17 17 17 Low birth weight The general clinical features of partial trisomy 9q include low birth weight, dolichocephaly, severe physical and mental retardation, stereotypic movement of the extremities, low set, malformed ears, deep set eyes, prominent, beaked nose, small, down turned mouth, microretrognathia, and long tapering fingers.8 [18][19][20][21][22] This patient, together with those previously reported with duplication of 9q34, provides evidence in support that the size of the duplication appears to influence the severity of the phenotype in partial duplication of 9q.…”

A Case of Partial Trisomy for the Long Arm of the X Chromosome

“…Karyotypically the proband's karyotype fairly corresponds to partial trisomy for the long arm of a no. 9 chromosome (Turleau et al 1975;Faed et al 1976). But her phenotype is different from that of the partial 9q trisomy case in showing a slightly small head without dolichocephaly, no slender face, no bulging forehead, no deep orbits, no beaked nose, normal form of the mouth and lip, a little small thorax, clinodactyly of both fifth fingers, no peculiar position of fingers, no amyotrophy on the lower limbs, and so on.…”

Partial trisomies 9 and 4 resulting from maternal translocation t(4; 9) (q25?; q13)

“…As far as we know, tertiary trisomy 9p or 9q-has been described in 20 families with reciprocal translocations. Eight cases out of them resulted from translocations between an acrocentric and a chromosome 9 (Rethor6 et al, 1973;Podruch and Weisskopf, 1974;Turleau et al, 1974;Balicek et al, 1975;Philippe et aL, 1975;Abe et aL, 1976;Lewandowski et al, 1976;Habedank and Faust, 1978), and the remaining 12 cases had translocations between a nonacrocentric chromosome and a chromosome 9 (Rott et al, 1971 ;Rethor6 et al, I973;Rethor6 et at., 1974;Schwanitz et aL, 1974;Centerwall et al, 1975;Lindenbaum and Bobrow, 1975;Mason et al, 1975;Penchaszadeh and Coco, 1975;Stoll et al, 1975;Sutherland et al, 1976;Moirot et al, 1977;Neu et at., 1979). In the latter group, it should be noted that the following three features were shared by all of the cases: (1) the 3 : 1 disjunction was derived from a maternal translocation; (2) no unbalanced offspring due to 2 : 2 segregation have been ascertained in the same family; and (3) the derivative chromosome 9, which was always shorter than the other translocation chromosome, had a breakpoint on its long arms and retained more or less the heterochromatic region (gqh).…”