J Korean Med Sci.  2012 Dec;27(12):1586-1590. 10.3346/jkms.2012.27.12.1586.

Reciprocal Deletion and Duplication of 17p11.2-11.2: Korean Patients with Smith-Magenis Syndrome and Potocki-Lupski Syndrome

• Lee CG
• Park SJ
• Yun JN
• Yim SY
• Sohn YB

• KMID: 2157987
• DOI: http://doi.org/10.3346/jkms.2012.27.12.1586

Abstract

Deletion and duplication of the -3.7-Mb region in 17p11.2 result in two reciprocal syndrome, Smith-Magenis syndrome and Potocki-Lupski syndrome. Smith-Magenis syndrome is a well-known developmental disorder. Potocki-Lupski syndrome has recently been recognized as a microduplication syndrome that is a reciprocal disease of Smith-Magenis syndrome. In this paper, we report on the clinical and cytogenetic features of two Korean patients with Smith-Magenis syndrome and Potocki-Lupski syndrome. Patient 1 (Smith-Magenis syndrome) was a 2.9-yr-old boy who showed mild dysmorphic features, aggressive behavioral problems, and developmental delay. Patient 2 (Potocki-Lupski syndrome), a 17-yr-old boy, had only intellectual disabilities and language developmental delay. We used array comparative genomic hybridization (array CGH) and found a 2.6 Mb-sized deletion and a reciprocal 2.1 Mb-sized duplication involving the 17p11.2. These regions overlapped in a 2.1 Mb size containing 11 common genes, including RAI1 and SREBF.

Keyword

Array-CGH; 17p11.2; Deletion; Duplication; Potocki-Lupski Syndrome (PTLS); Smith-Magenis Syndrome (SMS)

MeSH Terms

Adolescent
Asian Continental Ancestry Group/*genetics
Child, Preschool
*Chromosomes, Human, Pair 17
Comparative Genomic Hybridization
Developmental Disabilities/etiology/genetics
Gene Deletion
Gene Duplication
Humans
Intellectual Disability/etiology/genetics
Karyotyping
Male
Smith-Magenis Syndrome/diagnosis/*genetics
Sterol Regulatory Element Binding Protein 1/genetics
Transcription Factors/genetics
Sterol Regulatory Element Binding Protein 1
Transcription Factors

Figure

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  Fig. 1 Patient 1 showed broad forehead and downturned upper lip (A). Brachydactyly was noted (B).

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  Fig. 2 G-banded karyotype of patient 1 revealed 46, XY, del (17) (p11.2p11.2).

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  Fig. 3 Array CGH result of patient 1. (A) Array CGH data profile in whole chromosomes. A dot represents a bacterial artificial chromosome (BAC) clone, X-axis represents chromosome number (1-22, X, Y) and the Y-axis represents the log2 T/R signal ratio value. The table below the graph represents the average log2 T/R signal ratio value for each chromosome. Red dots represent a copy number loss (log2 T/R signal ratio value < -0.25) and deletion on chromosome 17. (B) Array CGH profile from chromosome 17 showed a deletion on the short arm, internal boundaries of the deletion in 17p11.2 (17,083,225-19,654,341), and its exact size (2.6 Mb) including RAI1 gene region.

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  Fig. 4 Array CGH result of patient 2. (A) Array CGH data profile in whole chromosomes. Green dots represent a copy number gain (log2 T/R signal ratio value > 0.25) and duplication on chromosome 17. (B) Array CGH profile from chromosome 17 showed a duplication on the short arm of, internal boundaries of the duplication in 17p11.2 (17,575,978-19,654,341), and its exact size (2.1 Mb).

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  Fig. 5 Schematic diagram of breakpoints for genes/regions on chromosome 17p11.2 of patient 1 and 2.

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