engleski

Duplication of pseudoautosomal region 1 and SHOX gene could be linked with characteristic phenotype

The reports on duplications of SHOX gene and pseudoautosomal region 1 (PAR 1) are scarce and thus the information on the possible phenotypic consequences is lacking. We report on five new patients from two families with large duplication of SHOX gene and downstream PAR 1 region. All of them were of normal or even short stature, with no signs of skeletal deformities or Mayer- Rokitansky-Kuster-Hauser type I syndrome. However all patients had a distinct phenotype, characterized with dysmorphic facial features (deep set eyes, high forehead, retrognathia), developmental delay/mental retardation, speech delay and stereotypic mouth movements which segregated with duplication of SHOX gene and PAR 1 in both families. So far, data on only 4 patients with large duplications of both SHOX gene and PAR 1 downstream of the SHOX gene have been published. In three of them mental retardation and dysmorphic features similar to those observed in our patients were described. Analysis of the size and position of duplications indicates that the ~50 kb large region of overlap between 626 kb and 678 kb, located in the PAR 1 could be responsible for the distinctive phenotype. It is very likely that duplications of SHOX gene and PAR 1, which still hasn’t been completely sequenced, are under- ascertained. With increasing application of molecular cytogenetic methods like MLPA, more patients with large duplication of the SHOX gene and PAR 1 or isolated PAR 1 will be eventually discovered delineating phenotypic consequences in more details.

PAR 1; SHOX

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