Unusual de novo Partial Trisomy 17p12p11.2 due to Unbalanced Insertion into 5p13.1 in a Severely Affected Boy

Abstract

Gain of copy numbers can be due to different chromosomal rearrangements such as direct or indirect duplications, translocations, small supernumerary marker chromosomes, or insertions. In a 3-year-old boy with dysmorphic features and developmental delay, chromosome analyses revealed a derivative chromosome 5. Microdissection and reverse fluorescence in situ hybridization identified the in 5p13.1 inserted part as 17p12-p11.2 material. Thus the patient suffered from a rare combination of genomic disorder, that is, Charcot-Marie-Tooth disease type 1A and Potocki-Lupski syndrome. Parental studies indicated that the abnormality was de novo in origin. As the question how this rearrangement arose cannot be answered conclusively, formal genetic counseling is warranted, which includes a discussion regarding the possibility of gonadal mosaicism. In conclusion, this case highlights that chromosome 17p is genetically relatively instable, and thus it can lead to rare chromosomal conditions.

Report of a patient with a de novo non-recurrent duplication of 17p11.2p12 and Yq11 deletion

“…Facial anomalies were identified in five patients, and included down-slanting palpebral fissures (2/5) with or without hypertelorism (3/5). Additionally, Mendez-Rosado et al [15] reported a patient sharing this duplication due to an unbalanced insertion in 5p13.1 (Table 1). Our patient shares some clinical characteristics with the above-described patients, including global developmental delay, short stature, hypotonia and some facial features (i.e., down-slanting palpebral fissures); however, he does not present congenital heart disease, renal abnormality or autistic features (he has no clinical difficulty with behavior, social interaction and communication) that have been characteristically reported in 70–100% of patients with PTLS [16].…”

Algoritmo para el diagnóstico de pacientes con trastornos del neurodesarrollo y sospecha de un síndrome genético

“…En un caso adicional, se realizó un estudio FISH más complejo para caracterizar un cromosoma 5 derivativo. 7…”