• Journal of Interdisciplinary Genomics
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• v.6 no.1
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• pp.1-5
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• 2024

Chromosome 22 is an acrocentric chromosome containing 500-600 genes, representing 1.5%-2% of the total DNA in cells. It was the first human chromosome to be fully sequenced by the Human Genome Project. Several syndromes involving the partial deletion or duplication of chromosome 22 are well descibed, including 22q11.2 deletion syndrome, 22q11.2 duplication syndrome, 22q11.2 distal deletion syndrome, Phelan-McDermid syndrome caused by a 22q13 deletion or pathogenic variant in SHANK3, and cat-eye syndrome caused by a 22 pter-q11 duplication. This review aims to provide concise information on the clinical characteristics of these syndromes. In particular, the similarities in features among these syndromes, genetic basis, and standard detection techniques are described, providing guidance for diagnosis and genetic counselling.

• Clinical and Experimental Pediatrics
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• v.57 no.6
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• pp.292-296
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• 2014

The deletion of the distal long arm of chromosome 1 is associated with a characteristic facial appearance and a pattern of associated malformations. Characteristic manifestations include a round face with prominent 'cupid's bow' and downturned corners of the mouth, thin vermilion borders of lips, a long upper lip with a smooth philtrum, a short and broad nose, epicanthal folds, apparently low-set ears, micrognathia, microcephaly, abnormal hands and feet, variable cardiac or genital anomalies, moderate to severe mental retardation, and growth retardation. Using fluorescent in situ hybridization (FISH) analysis to map precisely the deletion, we present a case of chromosome 1q44 deletion with craniofacial characteristics, multiple congenital anomalies, and growth and psychomotor retardation. In comparison with other reported cases of 1q43-44 deletion, the subject does not show hydrocephalus, seizure, syn- or polydactyly of hands, and a urogenital anomaly. However, an arachnoid cyst, pinpoint dimple on the midline of the forehead, a right-sided supernumerary nipple and auricular pit, polydactyly of the right foot, adducted thumb, and flexion restriction of the proximal interphalangeal joint with a simian line in both hands were observed additionally.

• Clinical and Experimental Pediatrics
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• v.46 no.1
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• pp.83-85
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• 2003

Deletion of the short arm of chromosome 6 is relatively rare, with the characteristic features of craniofacial malformations, hypotonia, and defects of the heart and kidney, with hydrocephalus and eye abnormalities. Here author reports a premature girl with bilateral anophthalmia, bilateral hydrocephalus and marked hypotonia, whose chromosome analysis revealed a 46, XX, del(6)(p23) chromosome constitution.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.10-13
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• 2016

Chromosome 11q13 deletion syndrome has been previously reported as either otodental syndrome or oculo-oto-dental syndrome. The otodental syndrome is characterized by dental abnormalities and high-frequency sensorineural hearing loss, and by ocular coloboma in some cases. The underlying genetic defect causing otodental syndrome is a hemizygous microdeletion involving the FGF3 gene on chromosome 11q13.3. Recently, a new form of severe deafness, microtia (small ear) and small teeth, without the appearance of eye abnormalities, was also reported. In this report, we describe a 1-year-old girl presenting with ptosis of the left upper eyelid, right auricular deformity, high-arched palate, delayed dentition, simian line on the right hand, microcephaly, and developmental delay. In this patient, we identified a deletion in the chromosome 11q13.2-q13.3 (2.75 Mb) region by using an array-comparative genomic hybridization analysis. The deletion in chromosome 11q13 results in a syndrome characterized by variable clinical manifestations. Some of these manifestations involve craniofacial dysmorphology and require a functional workup for hearing, ophthalmic examinations, and long-term dental care.

• Clinical and Experimental Pediatrics
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• v.58 no.8
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• pp.313-316
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• 2015

Interstitial deletions involving the chromosome band 15q22q24 are very rare and only nine cases have been previously reported. Here, we report on a 12-day-old patient with a de novo 15q22q23 interstitial deletion. He was born by elective cesarean section with a birth weight of 3,120 g at 41.3-week gestation. He presented with hypotonia, sensory and neural hearing loss, dysmorphism with frontal bossing, flat nasal bridge, microretrognathia with normal palate and uvula, thin upper lip in an inverted V-shape, a midline sacral dimple, severe calcanovalgus at admission, and severe global developmental delay at 18 months of age. Fluorescence in situ hybridization findings confirmed that the deleted regions contained at least 15q22. The chromosome analysis revealed a karyotype of 46,XY,del(15) (q22q23). Parental chromosome analysis was performed and results were normal. After reviewing the limited literature on interstitial 15q deletions, we believe that the presented case is the first description of mapping of an interstitial deletion involving the chromosome 15q22q23 segment in Korea. This report adds to the knowledge of the clinical phenotype associated with the 15q22q23 deletion.

• Journal of Genetic Medicine
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• v.14 no.1
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• pp.34-37
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• 2017

5p deletion syndrome, also known as Cri-du-Chat syndrome, is a chromosomal abnormality caused by a deletion in the short arm of chromosome 5. Clinical features of 5p deletion syndrome are difficult to identify prenatally by ultrasound examination, thus most cases of 5p deletion syndrome have been diagnosed postnatally. Here, we report eight cases of 5p deletion syndrome diagnosed prenatally, but were unable to find common prenatal ultrasound findings among these cases. However, we found that several cases of 5p deletion syndrome were confirmed prenatally when karyotyping was performed on the basis of abnormal findings in a prenatal ultrasound scan. Hence, it is necessary to carefully perform prenatal ultrasonography for detection of rarer chromosomal abnormalities as well as common aneuploidy.

• Journal of Genetic Medicine
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• v.11 no.1
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• pp.36-39
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• 2014

Chromosome 3 (3p) deletion syndrome is a rare genomic disorder caused by a deletion at the terminal end of the short arm of chromosome 3. The primary characteristics of the syndrome are delayed development, dysmorphic features, and several other congenital anomalies. Here, we describe the case of a 2-year-old Korean girl with typical features of 3p deletion syndrome, including dysmorphic facial features, low birth weight, developmental delay, growth and cognitive retardation, and congenital heart disease. This case represents the first report of 3p deletion syndrome in Korea. Although phenotypes can be variable among patients, a clinically recognizable pattern has been described for this genetic defect, and our report helps to identify other cases with 3p deletion syndrome from a clinical and genetic perspective.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1389-1389
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• 2005

The long arm duplication of chromosome 3 was reported for the first time in 1966 by Falek et al., and Hirschhorn et al. came to identify the duplication of 3q21${\rightarrow}$qter region in 1973. In most cases of duplication 3q syndrome patients, pure duplication of 3qter is believed to be rare and is often reported accompanied with deletion of another segment of the chromosome. Approximately 75 percent of parents of the patient in the meantime have been demonstrated to have unbalanced translocations or inversions of the chromosome. Partial deletion of the distal part of the short arm of chromosome 3 was first reported by Verjaal and De Nef in 1978 and terminal deletion of chromosome 3 (3p25-qter) has been observed in most cases. In karyotyping of chromosomes of immature infants showing the manifestations of flat occiputs, low set ears, hypertelorism, broad nasal roots, thin lips, web necks, hypotonia, hypertrichosis skin, cryptorchidism etc, we experienced a case diagnosed as 46,XY, rec(3)dup(3)(q21)del(3)(p25)inv(3)(p25q21).

• Journal of Genetic Medicine
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• v.8 no.1
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• pp.58-61
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• 2011

Cases of interstitial deletions of the long arm of chromosome 17 are very rare, with only nine cases ever reported worldwide. We describe a 12-year-old boy with profound developmental delay, microcephaly, facial dysmorphism, contracture of the large joints and bilateral hearing loss. A chromosomal study using a peripheral blood sampled revealed 46,XY,del(17)(q22q23). To our knowledge, he is the first case of interstitial deletion of the long arm of chromosome 17 ever reported in Korea.

• Journal of Genetic Medicine
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• v.18 no.2
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• pp.117-120
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• 2021

We experienced a case of Xq deletion -- 46,X,del(X)(q22.3) -- detected by abnormal noninvasive prenatal screening, subsequently diagnosed by amniocentesis. Genetic counseling was a challenge because there are few reports of prenatal diagnosis of Xq deletion. In each female cell, one X chromosome is inactivated at random early in development, and there may be a preferential inactivation of the abnormal X chromosome. But some proportions of genes escape inactivation. The most common manifestation in women with Xq deletion is primary or secondary ovarian failure. Critical regions for ovarian function may be located at the long arm of the X chromosome. But, the onset and the severity of ovarian failure may vary with diverse, intricate factors. We anticipate that noninvasive prenatal screening can identify the broader range of chromosomal or genetic abnormalities with the advances in technology and analytic methods. We report our case with a brief review of the literature.