Patient with trisomy 9p and a hypoplastic left heart with a tricentric chromosome 9

BackgroundTrisomy 9p is one of the most common partial trisomies found in newborns. We report the clinical features and cytogenomic findings in five patients with different chromosome rearrangements resulting in complete 9p duplication, three of them involving 9p centromere alterations.MethodsThe rearrangements in the patients were characterized by G-banding, SNP-array and fluorescent in situ hybridization (FISH) with different probes.ResultsTwo patients presented de novo dicentric chromosomes: der(9;15)t(9;15)(p11.2;p13) and der(9;21)t(9;21)(p13.1;p13.1). One patient presented two concomitant rearranged chromosomes: a der(12)t(9;12)(q21.13;p13.33) and an psu i(9)(p10) which showed FISH centromeric signal smaller than in the normal chromosome 9. Besides the duplication 9p24.3p13.1, array revealed a 7.3 Mb deletion in 9q13q21.13 in this patient. The break in the psu i(9)(p10) probably occurred in the centromere resulting in a smaller centromere and with part of the 9q translocated to the distal 12p with the deletion 9q occurring during this rearrangement. Two patients, brother and sister, present 9p duplication concomitant to 18p deletion due to an inherited der(18)t(9;18)(p11.2;p11.31)mat.ConclusionsThe patients with trisomy 9p present a well-recognizable phenotype due to facial appearance, although the genotype-phenotype correlation can be difficult due to concomitant partial monosomy of other chromosomes. The chromosome 9 is rich in segmental duplication, especially in pericentromeric region, with high degree of sequence identity to sequences in 15p, 18p and 21p, chromosomes involved in our rearrangements. Thus, we suggest that chromosome 9 is prone to illegitimate recombination, either intrachromosomal or interchromosomal, which predisposes it to rearrangements, frequently involving pericentromeric regions.

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“…2002 [ 17 ]; (10) Morrissette et al . 2003 [ 30 ]; (11) Zou et al . 2009 [ 15 ]; (12) Abu-Amero et al .…”

Section: Discussionmentioning

confidence: 99%

“…LDK and MIM coordinated the study and helped to draft the manuscript. All authors read and approved the final manuscript [ 30 , 31 ].…”

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confidence: 99%

Duplication 9p and their implication to phenotype

et al. 2014

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“…Patients with 9p trisomy exhibit mental retardation and characteristic head and facial abnormalities, such as microcephaly with large anterior fontanel and micrognathia, malformed protruding ears, hypertelorism, deep set eyes, and down slanting palpebral fissures [3,5]. Congenital heart defects [6,7], central nervous system abnormalities [8,9], kidney abnormalities [3,5], and skeletal malformations [10,11] are also present.…”

Section: Introductionmentioning

confidence: 99%

Long-term auxological and endocrinological evaluation of patients with 9p trisomy: a focus on the growth hormone-insulin-like growth factor-I axis

et al. 2014

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BackgroundTrisomy 9p is an uncommon anomaly characterised by mental retardation, head and facial abnormalities, congenital heart defects, kidney abnormalities, and skeletal malformations. Affected children may also show growth and puberty retardation with delayed bone age. Auxological and endocrinological data are lacking for this syndrome.MethodsWe describe three girls and one boy with 9p trisomy showing substantial growth failure, and we evaluate the main causes of their short stature.ResultsThe target height was normal in all families, ranging from 0.1 and -1.2 standard deviation scores (SDS). The patients had a low birth-weight (from -1.2 to -2.4 SDS), birth length (from -1.1 to -3.2 SDS), and head circumference (from -0.5 to -1.6 SDS). All patients presented with substantial growth (height) retardation at the time of 9p trisomy diagnosis (from -3.0 to -3.8 SDS).The growth hormone stimulation test revealed a classic growth hormone (GH) deficiency (GHD) in patients 1, 3, and 4. In contrast, patient 2 was determined to have a GH neurosecretory dysfunction (GHNSD). The plasma concentrations of IGF-I and IGFBP-3 were low in all patients for their ages and sexes (from -2.0 to -3.4 SDS, and from -1.9 to -2.8 SDS, respectively).The auxological follow-up showed that those patients who underwent rhGH treatment exhibited a very good response to the GH therapy, whereas patients 3 and 4, whose families chose not to use rhGH treatment, did not experience any significant catch-up growth.ConclusionsGH deficiency appears to be a possible feature of patients with 9p trisomy syndrome. These patients, particularly those with growth delays, should be evaluated for GH secretion.

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“…The results revealed an unusual case of de novo trisomy 9p in which an additional copy of the 9p13 → 9pter was inserted at 9qter. Although the distal half of the short arm of chromosome 9 (9p13 → 9pter) is responsible for the major clinical features of trisomy 9p [Fryns et al, 1979; de Pater et al, 2002], CHDs, including conotruncal defects, are uncommon [Tennstedt et al, 1999; Morrissette et al, 2003]. Subtelomeric FISH demonstrated that there was a cryptic subtelomeric deletion at the insertion breakpoint (9q34.3) on the 9qter, which might explain the CHDs in this patient.…”

Section: To the Editormentioning

confidence: 99%