• Clinical and Experimental Pediatrics
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• v.52 no.2
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• pp.242-246
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• 2009

The clinical features of ring chromosome 13 include mental and growth retardation, CNS anomalies, facial dysmorphism, cardiac defects, genital malformations, limb anomalies, skeletal deformities and anal malformations. Although many cases of ring chromosome 13 have been reported worldwide, only 6 cases have been reported in Korea, and the latter cases were not mosaic but pure ring chromosome 13. Here we report a case with mosaic ring chromosome 13. The baby boy was born at 37 weeks of gestation by induced vaginal delivery due to intrauterine growth restriction (IUGR). He was the second baby of a 28-year-old hepatitis B carrier mother and a 32-year-old father. There was no family history of chromosomal anomalies. The baby was a symmetric IUGR with a birth weight of 1,860 g, length of 44.8 cm, and head circumference of 29.4 cm. The physical examination revealed microcephaly, trigonocephaly, flat occiput, large ears, short neck and dysmorphic facial features, including microophthalmia, hypertelorism, antimongoloid slanting palpebral fissures, a flat nasal bridge, and micrognathia. The karyotype of this patient performed by peripheral blood lymphocytes was 46,XY,r(13)(p13q34)/45,XY,-13/46,XY,dic r(13;13)(p13q34;p13q34). The baby showed failure to thrive, hypotonia, and developmental delay. We report the first case of mosaic ring chromosome 13 in a male baby in Korea and compare this case with other Korean cases of non-mosaic ring chromosome 13.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.108-111
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• 2005

Ring chromosome 20 mosaicism [r(20)] is a rare chromosomal anomaly associated with minor dysmorphism, mental retardation, autistic behavior, and intractable epilepsy. The proposed mechanism of ring formation is breakage of both short and long arms of a chromosome with subsequent end-to-end fusion. We encountered an 18-month-old boy who presented with developmental delay and mental retardation with seizure episodes, but showed normal brain magnetic resonance imaging. Chromosome study from peripheral blood showed 46,XY, r(20)(p13q13.3) karyotype. The authors report a case of ring chromosome 20 with mental retardation and epilepsy, with a review of the literature.

• Clinical and Experimental Pediatrics
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• v.57 no.7
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• pp.333-336
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• 2014

Reports of constitutional ring chromosome 22, r(22) are rare. Individuals with r(22) present similar features as those with the 22q13 deletion syndrome. The instability in the ring chromosome contributes to the development of variable phenotypes. Central nervous system (CNS) atypical teratoid rhabdoid tumors (ATRTs) are rare, highly malignant tumors, primarily occurring in young children below 3 years of age. The majority of ATRT cases display genetic alterations of SMARCB1 (INI1/hSNF5 ), a tumor suppressor gene located on 22q11.2. The coexistence of a CNS ATRT in a child with a r(22) is rare. We present a case of a 4-month-old boy with 46,XY,r(22)(p13q13.3), generalized hypotonia and delayed development. High-resolution microarray analysis revealed a 3.5-Mb deletion at 22q13.31q13.33. At 11 months, the patient had an ATRT ($5.6cm{\times}5.0cm{\times}7.6cm$) in the cerebellar vermis, which was detected in the brain via magnetic resonance imaging.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.2
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• pp.63-67
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• 2007

A ring, monosomy and marker chromosome 13 was found in a 14 months old male with multiple congenital anomalies which suggested the deletion 13 syndrome. He presented development retardation, mental retardation, syndactyly of thumbs, xeroderma, dyspnea, dyslogia and face deformity diagnosed by chromosomal analysis using synchronized G-banding technique which revealed of 46,XY,r(13)(p13q34)[48]/45,XY,-13[28]/46,XY,-13,+mar[13]. We report this case with a brief review of the correlation between clinical features and the observed 13 polymorphism chromosome.