A case with 46,XX,del(11)(q23.2) karyotype and poor vision with literature review.

Summary: A case with 46,XX,del(ll)lq23.2) karyotype and poor vision with literature review: Here we describe clinical and cytogenetic data on a female child whom had been referred to our laboratory suspected to have Turner syndrome since she had webbed neck. Cytogenetic analysis revealed that she had deletion at 1 Iq23.2 to I lq terminal so her karyotype was ascertained as 46,XX,del( 11 >(q23.2). Her parents had normal karyotypes. In addition to many clinical features of del( 11 q ) syndrome the case had poor vision which is not common for this syndrome. Clinical features of this case and a few published cases will be reviewed briefly.Key-words: 11q terminal deletion disorder - Turner syndrome - Poor vision.INTRODUCTIONThe 1 lq terminal deletion disorder (previously called Jacobsen syndrome) is a recognized pattern of malformation caused by terminal deletion of the long (q) arm of chromosome 11 typically from band 11q23 to the telomere (1). Jacobsen (1 lq-) syndrome is a rare genetic disease (~1 in 100 000 live births). The subsequent loss of a large number of genes results in a complex and varied phenotype (1 ).Characteristic clinical signs include mild to moderate psychomotor retardation, failure to thrive, trigonocephaly, hypertelorism, wide or low nasal bridge, low-set malformed ears, microretrognathia, cardiac defects, digital anomalies, and thromboor pancytopenia (11,14).The human autosomal dominant nonsyndromic deafness DFNA12 has been mapped to a 36-cM interval on 1 Iq22-q24, between Dl 1S4I20 and Dl 1S912. Affected individuals display mild to moderately severe bilateral sensorineural hearing loss, mainly in the middle frequencies (500-2000 Hz) with a prelingual onset. Dl 1S925 maps in the middle of this region, cosegregating with DFNA12 in this pedigree.There is a gene called TECTA gene (tectorin alpha) which is located on II q22-q24 provides instructions for making a protein called alpha-tectorin. This protein is found in the inner ear, as part of a structure called the tectorial membrane. The tectorial membrane helps to convert sound waves to nerve impulses, a critical process for normal hearing.Alpha-tectorin interacts with other proteins to form the tectorial membrane. Two regions of the alpha-tectorin protein, called the vWFD domain and the zona pellucida domain, are important for protein interactions and assembly of the tectorial membrane.It has been demonstrated, Dl 1S925 and TECTA are physically linked, so TECTA represents a very good candidate for the DFNA12 locus. There is preliminary evidence that another locus for autosomal dominant nonsyndromic hearing impairment. (DFNA8) also maps to llq; this may represent another allele of DFNA12. Thus TECTA may also be considered a candidate for DFNA8 (13).The membrane ffizzled-related protein (MFRP) gene is located at cytogene location (1 lq23.3) and encodes a member of the ffizzeled related proteins family, some of which may play a role in eye development. Clq And Tumor Necrosis Factor Related Protein 5 (CTRP5) gene encodes a member of a family of proteins that function as components of basement membranes and may play a role in cell adhesion. Mutations in this gene have been associated with late-onset retinal degeneration. The protein may be encoded by either a bicistronic transcript including sequence from the upstream MFRP gene, or by a monocistronic transcript expressed from an internal promoter. The association of these genes with eye development has shown in some studies (17). Here we report a new case of deletion in the long arm of chromosome llq23 who had many clinical features of deletion llq syndrome in addition to poor vision and hearing and speech problems.CASE REPORTOur case was a 4 year old girl, a child of an unrelated healthy family. She was bom at term following a normal pregnancy. She had some of the main phenotypic characteristic features of Turner syndrome such as webbed neck. …