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.

Interstitial Deletion of 2q22.2q22.3 Involving the Entire ZEB2 Gene in a Case of Mowat-Wilson Syndrome.

Mowat-Wilson syndrome (MWS) is a rare autosomal dominant syndrome characterized by dysmorphic features, mental retardation, and congenital heart disease (CHD). MWS results from microdeletions of chromosome 2q23 or de novo SNVs involving the ZEB2 gene. Here, we report on an Egyptian MWS patient diagnosed by chromosomal microarray (CMA). A 1-year-old male child was referred to the CHD clinic, National Research Centre, presenting with dysmorphic features and CHD. The patient was referred to the human cytogenetics department for cytogenetic analysis and for screening of subtelomere rearrangements and microdeletion loci, using MLPA, and all revealed normal results. CMA revealed an interstitial 2.27-Mb microdeletion in chromosome 2q, involving the entire ZEB2 gene and other genes. This study emphasizes the significance of CMA in the detection of microdeletions/microduplications and as a screening tool in cases presenting with CHD and extracardiac manifestations. MWS should be suspected in patients presenting with the characteristic facial dysmorphism, developmental delay, seizures, Hirschsprung disease, and congenital heart anomalies, especially those involving the pulmonary arteries or pulmonary valves. It is recommended to include the ZEB2 locus in the MLPA microdeletions probes.

Clinical and genetic characterization of ten Egyptian patients with Wolf-Hirschhorn syndrome and review of literature.

BACKGROUND: Wolf-Hirschhorn syndrome (WHS) (OMIM 194190) is a multiple congenital anomalies/intellectual disability syndrome. It is caused by partial loss of genetic material from the distal portion of the short arm of chromosome. METHODS: We studied the phenotype-genotype correlation. RESULTS: We present the clinical manifestations and cytogenetic results of 10 unrelated Egyptian patients with 4p deletions. Karyotyping, FISH and MLPA was performed for screening for microdeletion syndromes. Array CGH was done for two patients. All patients exhibited the cardinal clinical manifestation of WHS. FISH proved deletion of the specific WHS locus in all patients. MLPA detected microdeletion of the specific locus in two patients with normal karyotypes, while array CGH, performed for two patients, has delineated the extent of the deleted segments and the involved genes. LETM1, the main candidate gene for the seizure phenotype, was found deleted in the two patients tested by array CGH; nevertheless, one of them did not manifest seizures. The study emphasized the previous. CONCLUSION: WHS is a contiguous gene syndrome resulting from hemizygosity of the terminal 2 Mb of 4p16.3 region. The Branchial fistula, detected in one of our patients is a new finding that, to our knowledge, was not reported.

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.

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.