IGF1R, IGFALS, and IGFBP3 gene copy number variations in a group of non-syndromic Egyptian short children.

BACKGROUND: Insulin-like growth factor-1 (IGF-1) is required for normal intrauterine and postnatal growth, and this action is mediated through IGF1 receptor (IGF1R). IGF1R copy number variants (CNVs) can cause pre- and postnatal growth restriction, affecting an individual's height. In this study, we used multiplex ligation-dependent probe amplification (MLPA) to detect CNVs in IGF1R, IGFALS, and IGFBP3 genes in the diagnostic workup of short stature for 40 Egyptian children with short stature. RESULTS: We detected a heterozygous deletion of IGF1R (exons 4 through 21) in 1 out of the 40 studied children (2.5%). Meanwhile, we did not detect any CNVs in either IGFALS or IGFBP3. CONCLUSION: The diagnostic workup of short stature using MLPA for CNVs of IGF1R and other recognized height-related genes, such as SHOX and GH, in non-syndromic short stature children can be a fast and inexpensive diagnostic tool to recognize a subcategory of patients in which growth hormone treatment can be considered.

The detection of steroid sulfatase gene deletion (STS) in Egyptian males with X-linked ichthyosis.

BACKGROUND: Ichthyosis is a disorder of keratinization characterized by diffuse uniform and persistent scales resulting from abnormal epidermal differentiation or metabolism. The identification of steroid sulfatase (STS) as the cause of X-linked ichthyosis (XLI) points to the importance of this enzyme in skin desquamation. Fluorescent in situ hybridization (FISH) analysis is a good diagnostic technique with which to detect a common deletion of the STS gene. OBJECTIVE: In this study, the authors set out to detect the X-linked type of ichthyosis, diagnosed by detection of STS gene deletions among Egyptian males. METHODOLOGY: Egyptian males complaining of X-linked ichthyosis were clinically examined, evaluating pedigree analysis of the family, cytogenetic studies using G-banding technique and FISH using locus specific probe for steroid sulfatase (STS) gene which is located at chromosome Xp22.3. RESULTS: Of patients, 11.11 percent had nocturnal enuresis and 33.33 percent showed STS gene deletion by FISH analysis. CONCLUSION: This study underlines a difficulty in diagnosing X-linked ichthyosis on the clinical features or familial pedigree analysis in Egypt and the importance of cytogenetic and molecular cytogenetic studies for diagnosis. FISH analysis is a good, reliable and rapid diagnostic tool with which to detect STS gene deletion. Since FISH will not detect partial deletion or point mutations, the authors recommend further molecular studies to reach the proper diagnosis of X-linked ichthyosis.

Phenotypic characterization of rare interstitial deletion of chromosome 4.

Interstitial deletion of the long arm of chromosome 4 is rare. Patients with interstitial deletion of the long arm of chromosome 4 differ from those with terminal deletions. Phenotypes may be variable, depending upon the specific length and location of the deleted portion. Here, we report on a boy exhibiting most of the congenital malformations encountered in terminal 4q syndrome. The conventional karyotyping and Fluorescence in-situ hybridization revealed a de novo interstitial del (4)(q31q32). The current report is a further document highlighting that deletion of segment q31 could be contributing to the expression of most of the phenotype of 4q deletion syndrome. Using array comparative genome hybridization methodology is recommended for investigating further cases with similar segmental interstitial deletions to support and delineate findings and to define genes implicated in the pathogenesis of the disorder.