Tandem triplication of chromosome 13q14 with inverted interstitial segment in a 4 year old girl

17p11.2p12 triplication and del(17)q11.2q12 in a severely affected child with dup(17)p11.2p12 syndrome

“…The mechanism of duplication coupled with mosaic triplication in our patient could be because of an aberrant recombination during meiosis I followed by an intrachromosomal mitotic event resulting in mosaicism, similar to that described for other mosaic triplication cases (56). It is observed, in general, that tetrasomy of an autosomal segment causes a similar but more severe phenotype than trisomy of the same segment as demonstrated in tetrasomy 9p, 18p, and 15(q12-q13) (49). Thus, we can attribute the severity of the phenotype in our patient to increased copy number of dosage sensitive genes in 17p11.2p12 and unusual features to 17q11.2q12 deletion.…”

“…We also report here for the first time a patient with tetrasomy 17p11.2p12. Triplications or partial tetrasomies for other chromosomal regions have been reported (Table 4) (48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)(61)(62). Constitutional triplications of genomic regions have been associated with various disorders that include mental retardation syndromes, Pelizaeus-Merzbacher syndrome, Parkinsonism and recently, hereditary pancreatitis (63)(64)(65)(66).…”

A complex medical phenotype in a patient with triplication of 2q12.3 to 2q13 characterized with oligonucleotide array CGH

“…Paternal interchomosomal origin, as in this present case, has been described for triplications of e.g. 13q14 and 15q11 ] q13 (Wang et al, 1999;Brecevic et al, 2000;Ungaro et al, 2001).…”

“…12p leading to Pallister-Killian syndrome is only seen in mosaic form (Brecevic et al, 2000). Cytogenetically visible interstitial triplications are also rare but have been reported for 2q11.2 ] q21, 2q37, 5p15.33 ] p14, 7p21.3 ] p21.2, 9p22 ] p13, 10q26, 13q14, 13q21.1 ] q21.33, 15q11 ] q13 and 22q11.2 (Brecevic et al, 2000;Yobb et al, 2005;Lopez-Exposito et al, 2008). Triplication of proximal 15q an intrachromosomal triplication of 2q12.3 ] q13.…”

“…As part of the investigation, chromosome analysis was performed and showed Tetrasomy usually gives rise to a more severe phenotype than trisomy which helps explain why most tetrasomies are rare and why tetrasomy for e.g. 12p leading to Pallister-Killian syndrome is only seen in mosaic form (Brecevic et al, 2000). Cytogenetically visible interstitial triplications are also rare but have been reported for 2q11.2 ] q21, 2q37, 5p15.33 ] p14, 7p21.3 ] p21.2, 9p22 ] p13, 10q26, 13q14, 13q21.1 ] q21.33, 15q11 ] q13 and 22q11.2 (Brecevic et al, 2000;Yobb et al, 2005;Lopez-Exposito et al, 2008).…”