CLINICAL FEATURES OF A CASE WITH 46,XX,del(18)(p11.1p11.3).

The deletion 18p syndrome is the second most frequent autosomal deletion syndrome which is present in approximately 1/40,000 live births. Since the first report of the deletion 18p in 1963, more than 150 cases have been reported.Most cases (about 2/3) are de novo deletions. The short arm of chromosome 18 is about 16 Mb in size (2). It is divided in three sub bands: pi 1.1 adjacent to the centromere, pi 1.2 subdivided in pi 1.21, pi 1.22 and pi 1.23, and pi 1.3 subdivided in pi 1.31 and pi 1.32 (10). 18pl 1.1 is an apparent and frequent breakpoint cluster in non-mosaic patients with de novo deletion of 18p ( 10). Here we report a de novo case of an interstitial deletion on the short arm of chromosome 18 which has not been reported previously.Our case was an 8 year old girl, a child of an unrelated healthy family. She was born at term following a normal pregnancy. She had some abnormal facial features such as frontal bossing, wide nasal bridge, small mouth with thin upper lip and smooth area above the upper lip. The chin was slightly smaller than normal. The child had mental retardation, developmental delay and speech problems. In addition, she had an anterior fistula in palate ( 1.5x 3 cm2). Facial artery musculomucosl flap (FAMM). FAMM flap surgery was done for her at age 4.5 year (Fig. 1).When she was 7, three small stones were found in right kidney and two ones in major calyx of left kidney.Cytogenetic analysis of phytohemagglutinin (PHA) stimulated peripheral blood sample was performed using standard protocol. All cells examined showed deletion on the short arm of chromosome 18. Her mother and father were investigated and found to have normal karyotypes. Therefore, the karyotype of the patient was ascertained as 46,XX,del( 18))(p 11.1 p 11.3). (Fig. 2).More than 20 genes with critical roles have been reported on the short arm of chromosome 18. Some diseases have also been reported in association with these genes. Mutations in one of these genes including the absence of all or part of the short arm of one chromosome 18 (deletion 18p syndrome), deafness autosomal recessive 46 related to 18pll.32-p 11.31, Porokeratosis, disseminated superficial actinic related to 18p 11.3, nonsyndromic holoprosencephaly related toTGIF 1 gene located ini8pl 1.3 and Majeed syndrome 18pll.31 results from mutations in the LPIN2 gene located in 18pl 1.31.Previously the association between chromosomes 2,9,10,16,19, and X abnormalities and kidney stone has been reported. (1).Kidney abnormalities including kidney stones has been seen in children with tetrasomy 18p and ring chromosome 18 mostly originated from 18p, with an estimated size of less than 10 cm (7).Several different kinds of kidney problems including infections in the urinary tract resulted from no correctly Urine elimination and Tos et al. reported an 8-year-old girl with mental deficiency, growth deficiency, round face, flat nasal bridge, micrognathia and hypotonia. Cytogenetic studies revealed de novo 45,XX,der(18)del(18)t(18;21) karyotype (9).Bora et al. reported an unusual case with 45,XY,del( 18)t( 18;21 ), -21 karyotype who had speech delay, open mouth and drooling saliva, hyperactive movements, flat nasal bridge, prominent ears, micrognathia, hypotonia, and overriding of left 3rd on 2nd toe (2).Browning recognized immunoglobulin (Ig) A deficiency in a case with chromosome 18p deletion syndrome (46,XX,del( 18)(pl 1.1)) (3).A report presented a patient with a partial deletion on the short arm of chromosome 18 (del (18) (pi 1.3).), who had dysmorphic features, delayed developmental milestones and congenital heart disease (12). Wester et al. studied a genotype-phenotype correlation of seven cases with de novo 18p deletions and found that there might be a critical region between 18pl 1.1 and 18p 11.21 responsible for normal mental development (11).A 2 month old male infant was reported to have mild growth retardation, prominent forehead, low set ears, low nasal bridge, rounded faces, cleft palate, webbed neck, shawl scrotum, and absent right kidney exhibiting a mixed clinical picture with features of both 18p- and partial trisomy 16pl3. …