A case of ring chromosome 15 accompanied by almost normal intelligence

Kitatani, M.; Takahashi, Hiroaki; Ozaki, Mamoru; Okino, Eizo; Maruoka, Tatsuya

doi:10.1007/bf00276343

Cited by 10 publications

(5 citation statements)

References 4 publications

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“…The level of mosaicism of the ring chromosome, tissue-specific variation in this mosaicism, variation in the amount of euchromatin, the mitotic instability of the ring chromosome and parent of origin of the r(15) chromosome have all been proposed as contributing to the phenotype (Butler et al 1988;Horigome et al 1992;Kitatani et al 1990;Nuutinen et al 1995;Roback et al 1991;Schinzel 2001;Smith et al 1991). The results of FISH analyses in both cases demonstrated loss of the subtelomeric region, consistent with the most common mechanism proposed for ring chromosome formation; short arm and long arm breaks with rejoining.…”

Section: Discussionmentioning

confidence: 99%

“…Alternatively, the ring chromosome may occur as a supernumerary ring, resulting in a duplication or trisomy for the genetic material contained within the ring. In unbalanced ring chromosomes, the clinical phenotype may vary greatly depending in part on the loss of euchromatin distal to the breakpoints (Fryns et al 1986;Kitatani et al 1990;Kosztolanyi 1987;Kosztolanyi et al 1991;Tumer et al 2004). In addition, phenotypic abnormalities may result from further substantive gene loss following chromosome breakage and reunion during cell division.…”

Section: Introductionmentioning

confidence: 99%

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Ring chromosome 15: characterization by array CGH

et al. 2005

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Ring chromosome 15 [r(15)] is an uncommon finding with less than 50 patients reported. Precise genotype-phenotype correlations are problematic because of the difficulties in determining the extent of euchromatic loss, the level of mosaicism, and the influence of the timing of ascertainment. We report two discordant examples of r(15) patients. In the first case, prenatal diagnosis of a de novo r(15) was made during the second trimester: mos 46,XX,r(15)(p11.2q26)[32]/45,XX,-15[13]/47,XX,r(15)(p11.2q26)x2[3]/46,XX,dic r(15)(p11.2q26p11.2q26[1]/46,XX[2]. Postnatal follow-up revealed extremely small stature, heart defects, and developmental delay. Patient 2 was a 31-year-old short-statured female who was living independently: 46,XX,r(15)(p11q26). Both cases showed loss of the 15q subtelomeric region by fluorescence in situ hybridization (FISH). To investigate the discordance in phenotypes between the two patients, we undertook array comparative genomic hybridization (array CGH) analyses to more fully characterize the deletions associated with these otherwise structurally indistinguishable r(15) chromosomes from conventional cytogenetic analyses and fluorescence in situ hybridization (FISH) studies. By array CGH, patient 1 showed deletion of multiple contiguous clones predicting an approximately 6 Mb deletion of distal 15q. In contrast, patient 2 showed loss of just the 15q subtelomeric clone and an interstitial clone by array CGH confirming that the severity of the phenotype correlated with the size of the deletion at the molecular level. These cases illustrate the utility of array CGH characterization for determining the size of the associated deletion in ring chromosomes and for facilitating phenotype-genotype correlations.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ring chromosome 15: characterization by array CGH

et al. 2005

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“…These children have variable characteristics, including intrauterine growth retardation, different degrees of postnatal growth failure, a triangular facies, fifth-finger clinodactyly. and, occasionally, café-au-lait spots and a discrepancy in leg length (Fryns et al" 1979(Fryns et al" , 1986) with variable develop mental and speech delay (Kitatani et al" 1990). Interestingly, many of these phenotypic findings are also present in patients with Russell-Silver syndrome, a mostly sporadic condition of unknown molecular basis that is not associated with a particu lar chromosome abnormality (Saal et al, 1985).…”

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confidence: 88%

Hemizygosity at the insulin-like growth factor I eceptor (IGF1R) locus and growth failure in the ring chromosome 15 syndrome

Peoples

Milatovich²,

Francke

1995

Cytogenet Genome Res

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The ring chromosome 15 syndrome is characterized by mild-to-severe growth failure. We evaluated the status of the insulin-like growth factor I receptor (IGF1R) gene, which had previously been assigned to band 15q26 in several patients with de novo ring 15 chromosomes, to investigate a possible correlation between disruption or loss of the IGF1R gene with the severe growth failure phenotype. The presence or absence of the IGF1R gene on the ring 15 chromosomes of five patients was ascertained by in situ hybridization and gene-dosage (Southern) blotting. The location of the breakpoints was determined by typing polymorphic markers from the distal end of the long arm of chromosome 15 in both the probands and their parents. Deletion mapping determined that all breakpoints were distal to D15S100 and that the IGF1R gene is located between D15S107 and D15S87. Three patients who had suffered severe growth failure in early childhood were hemizygous at the IGF1R locus, while one patient with borderline short stature had two copies of the IGF1R gene. The correlation between IGF1R gene dosage and growth retardation demonstrated here in our ring chromosome 15 patients suggests a possible role for heterozygous IGF1R gene mutations or deletions in other cases of unexplained growth failure.

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“…His relative height and predicted adult height improved continuously on GH therapy. During the two years of treatment his growth velocity increased from 5 9 cm/year to 8 5 cm/year, that is, by 44% and his relative height improved by [1][2][3][4][5][6][7][8] SD, that is to -4 4 SD (table 2). His predicted adult height assessed according to the Roche-Wainer-Thissen method (RWT)'0 increased during the same time from 159-6 cm to 163-5 cm (table 2).…”

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confidence: 99%

Good growth response to growth hormone treatment in the ring chromosome 15 syndrome.

Nuutinen

Kouvalainen

Knip

1995

Journal of Medical Genetics

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Ring chromosome 15 syndrome is a rare condition in which severe growth retardation is a major finding. We report a 4 year old boy with the karyotype 46,XY, r(15)(pll.2q26.2) whom we have treated with recombinant human growth hormone (GH) for two years. During the first year oftreatment, the insulin-like growth factor I increased from subnormal 4-2 nmol/I to normal 13 8 nmol/l and the insulin-like growth factor binding protein 3 levels increased from 2*6 to 3 8 mg/l, whereas high binding protein 1 concentrations normalised from 52 0 to 16-7 ttgIl. During the two years of treatment his relative height improved from -6*2 SD to -4.4 SD and the predicted adult height from 159-6cm to 163-5 cm. Owing to the good growth response, we have decided to continue GH treatment. (J Med Genet 1995;32:486-487)

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A case of ring chromosome 15 accompanied by almost normal intelligence

Abstract: A further case of ring chromosome 15 in a 12-year-old boy with growth failure is described. He had minor congenital anomalies, but almost normal intelligence.

Cited by 10 publications

References 4 publications

Ring chromosome 15: characterization by array CGH

Ring chromosome 15: characterization by array CGH

Hemizygosity at the insulin-like growth factor I eceptor (IGF1R) locus and growth failure in the ring chromosome 15 syndrome

Good growth response to growth hormone treatment in the ring chromosome 15 syndrome.

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