Prenatal genetic diagnosis of a case with ring chromosome 13 / 中华医学遗传学杂志

OBJECTIVE@#To carry out cyto- and molecular genetic analysis for a fetus with a ring chromosome identified through non-invasive prenatal testing (NIPT).@*METHODS@#A pregnant woman presented at the Shengjing Hospital Affiliated to China Medical University on May 11, 2021 was selected as the study subject. Maternal peripheral blood sample was screened by NIPT, and G-banded chromosomal karyotyping was carried out on amniotic fluid and peripheral blood samples from the couple. The fetus and the pregnant woman were also subjected to genomic copy number variation sequencing (CNV-seq), chromosomal microarray analysis (CMA), and fluorescence in situ hybridization (FISH) assay.@*RESULTS@#NIPT result suggested that the fetus had monomeric mosaicism or fragment deletion on chromosome 13. G banded chromosomal analysis showed that both the fetus and its mother had a karyotype of 47,XX,der(13)(pter→p11::q22→q10),+r(13)(::p10::q22→qter::), whilst her husband had a normal karyotype. FISH has verified the above results. No abnormality was detected with CNV-seq and CMA in both the fetus and the pregnant woman.@*CONCLUSION@#The ring chromosome 13 in the fetus has derived from its mother without any deletion, duplication and mosaicism. Both the fetus and the pregnant woman were phenotypically normal.

Clinical features and genetic analysis of two fetuses with ring chromosome 21 mosaicism / 中华医学遗传学杂志

OBJECTIVE@#To investigate the perinatal clinical phenotype and genetic characteristics of two fetuses with ring chromosome 21 mosaicisms.@*METHODS@#Two fetuses who were diagnosed at the Xiamen Maternal and Child Health Care Hospital in November 2021 were selected as the study subjects. Clinical data of the two fetuses were collected. Conventional G-banded karyotyping and chromosomal microarray analysis (CMA) were carried out for the fetuses and their parents.@*RESULTS@#Prenatal ultrasonography of fetus 1 has revealed absence of nasal bone, ventricular septal defect, persistent left superior vena cava, and mild tricuspid regurgitation. Chromosomal karyotyping was 46,X?,dic r(21;21)(p12q22;q22p12)[41]/45,X?,-21[9]. CMA has revealed a 30.00 Mb quadruplication at 21q11.2q22.3 and a 3.00 Mb deletion at 21q22.3. For fetus 2, ultrasonography has revealed pointed echo of the nasal bone. The fetus was found to have a karyotype of 46,X?,r(21)(p12q22)[83]/45,X?,-21[14]/46,X?,dic r(21;21)(p12q22;q22p12)[3]. CMA has revealed a 5.10 Mb quadruplication at 21q22.12q22.3 and a 2.30 Mb deletion at 21q22.3.@*CONCLUSION@#The perinatal phenotype of the two fetuses with ring chromosome 21 mosaicisms is related to the duplication of chromosomal segments near the breakpoints of the chromosomal deletions. The combined chromosomal karyotyping and CMA has enabled prenatal diagnosis and genetic counseling for these families.

Clinical phenotype and genetic analysis of twelve children with ring chromosomes / 中华医学遗传学杂志

OBJECTIVE@#To explore the prevalence and clinical manifestations of ring chromosomes among children featuring abnormal development.@*METHODS@#From January 2015 to August 2021, 7574 children referred for abnormal development were selected, and their peripheral blood samples were subjected to G-banded chromosomal karyotyping analysis.@*RESULTS@#Twelve cases of ring chromosomes were detected, which have yielded a prevalence of 0.16% and included 1 r(6), 2 r(9), 1 r(13), 1 r(14), 2 r(15), 1 r(21) and 3 r(X). The children had various clinical manifestations including growth and mental retardation, limb malformation, and congenital heart disease. For two children with r(9) and two with r(15) with similar breakpoints, one child with r(9) and one with r(15) only had growth retardation, whilst another with r(9) and another with r(15) also had peculiar facies and complex congenital heart disease. The r(X) has featured some manifestations of Turner syndrome.@*CONCLUSION@#Ring chromosomes are among the common causes for severe growth and mental retardation in children with diverse clinical phenotypes. Clinicians should pay attention to those with developmental anomalies and use chromosomal analysis to elucidate their genetic etiology.

Genetic features of a case with mosaic ring chromosome 4 and a review of the literature / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis, clinical phenotype and pathogenesis for a child with mosaicism ring chromosome 4.@*METHODS@#Clinical data of the child was collected. Peripheral blood chromosomal karyotype G banding analysis, chromosomal microarray analysis (CMA), fluorescence in situ hybridization (FISH) were carried out for the child, in addition with a review of the literature.@*RESULTS@#The child was born full-term with low birth weight, facial dysmorphism, patent ductus arteriosus and ventricular septal defect. His karyotype was determined as mos46,XY,r(4)(p16.3q35.2)[259]/45,XY,-4[25]/47,XY,r(4)(p16.3q35.2), +r(4)(p16.3q35.2)[8]/46,XY,der(4)del(4)(p16.3)inv(4)(p16.3q31.1)[6]/46,XY,dic?r(4;4)(p16.3q35.2;p16.3q35.2)[4]/48,XY,r(4)(p16.3q35.2),+r(4)(p16.3q35.2)×2[3]/46,XY,r(4)(p1?q2?)[2]; CMA result was arr[GRCH37]4p16.3(68 345-2 981 614)×1; FISH result was 45,XY,-4[12]/45,XY,-4×2,+mar1.ish r1(4)(WHS-,D4Z1+)[1]/ 46,XY,-4,+mar1.ishr1(4)(WHS-,D4Z1+)[73]/46,XY,-4,+mar2.ishr2(4)(WHS-,D4Z1++)[1]/47,XY,-4,+mar1×2.ishr1(4) (WHS-, D4Z1+)×2[4]/46,XY,del(4)(p16.3).ish del(4)(p16.3)(WHS-,D4Z1+)[9].@*CONCLUSION@#In this case, the ring chromosome 4 as a de novo variant has produced a number of cell lines during embryonic development and given rise to mosaicism. The clinical phenotype of ring chromosome 4 is variable. The instability of the ring chromosome itself, presence of mosaicism, chromosome breakpoint and range of deletion and/or duplication may all affect the ultimate phenotype.

Cromosomopatías en pacientes con cáncer sometidos a radioterapia con cobalto 60 / Chromosomopathies in cancer patients undergoing cobalt 60 radiotherapy

Objetivo: Describir las aberraciones citogenéticas que pueden ser observadas por medio de la técnica Giemsa en fluorescencia y encontradas en pacientes con cáncer antes y después de ser sometidos a tratamiento con radioterapia. Métodos: Se analizó un mínimo de 200 metafases en primera división mitótica antes y después del tratamiento de radioterapia en nueve pacientes que asistieron a la sección de radioterapia del Hospital San Juan de Dios Costa Rica. En cada caso se contabilizó cada tipo de cromosomopatía por medio de la prueba de Giemsa en fluorescencia y utilizando bromodeoxiuridina y naranja de acridina. Resultados: Las cromosomopatías producidas por radioterapia se observaron tanto antes como después del tratamiento sin embargo destacó el incremento en la frecuencia de los cromosomas dicéntricos y anillos céntricos una vez finalizada la terapia. La frecuencia de fracturas cromatídicas de asociaciones satelíticas y de alteraciones morfológicas no se ve afectada por la radioterapia. Uno de los participantes presentó un recuento mitótico bajo. Conclusión: La radioterapia aumenta significativamente la frecuencia de los cromosomas dicéntricos y dicéntricos más anillos en la muestra en estudio. Este trabajo es relevante por ser el primer estudio en Costa Rica en el que se analizan los cromosomas dicéntricos como biomarcadores de exposición a radiaciones ionizantes mediante la prueba de Giemsa en fluorescencia y utilizando bromodeoxiuridina y naranja de acridina.

Aim: The objective of this study was to describe the before and after cytogenetic aberrations found in current patients of radiotherapy. This can be observed through the technique called "Giemsa in fluorescence" Methods: A minimum of 200 metaphases were analyzed in the first mitotic division in 9 patients. The patients where observed before and after radiotherapy treatment at the San Juan de Dios Hospital in Costa Rica. In each case any type of chromosomopathy was counted using the "Giemsa in fluorescence" test as well as Bromodeoxyuridine and acridine orange. Results: The chromosomopathies are observed before and after treatment with radiotherapy. The treatment seems to change the frecuency increasing the dicentric chromosomes and centric rings after the treatment. The frequency of chromatid fractures satellite associations and morphological alterations were not affected by radiotherapy. Conclusion: The chromosomopathies produced by radiotherapy were observed both before and after treatment with variations in their frequency. After radiotherapy dicentric chromosomes and dicentric chromosomes plus rings frequencies increased significantly. A low mitotic count was present this could have been the result of radiation on the bone marrow or by the cell repair and apoptosis system. The standardized " Fluorescence Plus Giemsa" test using Bromodesoxyuridine and acridine orange was used for the fiesta time in Costa Reica. This allowed for the measurement of radiation exposure used in the treatment or detection of diseases and cancer in pacients.

A rare case of dicentric ring chromosome and derivative ring chromosome Chimera / 中华医学遗传学杂志

OBJECTIVE@#Utilize high-resolution chromosome analysis and microarray detection to determine the genetic etiology of infertility of a 32-year old female patient.@*METHODS@#The peripheral blood of the patient was cultured for high-resolution chromosome G and C banding karyotype analysis, and then 750K SNP-Array chip detection was performed.@*RESULTS@#Karyotype analysis results showed that the patient's karyotype was 45,XX,-13 [7]/46,XX,r(13) (p13q34) [185]/46,XX,dic r(13;13)(p13q34;p13q34) [14]/ 47,XX,+der(13;13;13;13) (p13q34;p13q34;p13q34; p13q34), dic r(13;13) [1]/ 46,XX [3]. The microarray results showed that the patient had a 3.3 Mb deletion in the 13q34 segment of chromosome 13, which may be related to infertility.@*CONCLUSION@#Infertility of the patient reported in this article may be related to the deletion of chromosome segment (13q34-qter).

Molecular cytogenetic study of a case with ring chromosome 15 / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a patient featuring developmental delay.@*METHODS@#The patient and her parents were subjected to G- and C-banded chromosomal karyotyping analysis. The proband was also analyzed by single nucleotide polymorphism microarray (SNP-array). The result was verified by using fluorescence quantitative PCR (qPCR).@*RESULTS@#The proband's karyotype was ascertained as 46,XX, r(15)(p11.2q26.3)[92]/45,XX,-15[9]/46,XX, dic r(15)(p11.2q26.3;p11.2q26.3)[4]. SNP-array revealed that she has carried a de novo deletion at 15q26.3 (98 957 555-102 429 040) spanning approximately 3.4 Mb, which encompassed the IGF1R gene. qPCR has confirmed haploinsufficiency of exons 3, 10 and 20 of the IGF1R gene. Both of her parents had a normal karyotype.@*CONCLUSION@#The abnormal phenotype of the proband may be attributed to the microdeletion at 15q26.3, in particular haploinsuffiency of the IGF1R gene and instability of the ring chromosome. Cytogenetic method combined with SNP-array and qPCR can efficiently delineate chromosomal aberrations and provide accurate information for clinical diagnosis and genetic counseling.

Kleefstra syndrome 1 and ring chromosome 9 in a case / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical and molecular genetic characteristics of patient with Kleefstra syndrome 1.@*METHODS@#Clinical data, chromosomal karyotype and whole genome copy number variations (CNVs) of the patient were analyzed.@*RESULTS@#The patient was found to have a karyotype of 45,XX,-9[4]/46,XX,r(9)(p24q34)[56]. Whole-genome CNVs detection revealed that she has carried a heterozygous deletion of approximately 670 kb at 9q34.3, which encompassed the entire EHMT1 gene. The region is strongly associated with Kleefstra syndrome (1/9q telomere deletion). In addition, the patient also had heterozygous deletion of 9pter, which may predispose to formation of ring chromosome 9.@*CONCLUSION@#The child was diagnosed with Kleefstra syndrome type 1 in conjunct with ring chromosome 9.

Molecular cytogenetic diagnosis of a case with ring chromosome 18 syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with developmental delay and congenital syndactyly.@*METHODS@#G-banding chromosomal karyotyping and chromosomal microarray analysis (CMA) were performed on peripheral blood sample from the child.@*RESULTS@#The child was ascertained as 46, XY, r(18)[52]/45,XY,?18[3]. A 18q21.32-q23 deletion was identified by CMA with a size of 19.85 Mb, which has encompassed 99 genes including CTDP1, TXNL4A, TSHZ1, PIGN, RTTN, TNFRSF11A, KDSR and CYB5A.@*CONCLUSION@#Clinical phenotype of the patient with ring chromosome 18 is associated with the size of the euchromatin loss and involved genes. As a useful complement to conventional karyotyping, CMA has provided an powerful tool for delineating complex chromosomal aberrations.

Complex karyotype including ring chromosome 11 in a patient with acute myeloid leukemia: case report

ABSTRACT CONTEXT: Complex karyotypes in acute myeloid leukemia (AML) are characterized by an overall low response rate with frequent relapses after clinical treatment. CASE REPORT: Here, we describe the case of a 61-year-old obese female with clinically diagnosed AML who presented a complex karyotype involving an uncommon abnormality: ring chromosome 11. Immunophenotypic analysis confirmed the diagnosis. Classical and molecular cytogenetic analyses, using GTG banding and FISH (fluorescence in situ hybridization), revealed the presence of complex structural rearrangement involving r(11), add(12)(p13), der(5) and der(13). CONCLUSIONS: Molecular cytogenetic analysis is suitable for better identification and characterization of chromosomal rearrangements in AML. Case reports like this, as well as population-based studies, are necessary for understanding the karyotypic changes that occur in humans.

Síndrome del anillo del cromosoma 18: reporte de un caso y revisión de la literatura / Chromosome 18 ring syndrome: case report and review of the literature

El Síndrome del Anillo del Cromosoma 18 (18 [(r)18]) es un trastorno cromosómico que se incluye dentro de las anomalías estructurales desequilibradas donde dicho cromosoma se encuentra en forma de anillo el cual resulta de la pérdida simultánea de ambos segmentos terminales de los brazos corto y largo con la subsecuente fusión de sus extremos, constituyendo una estructura circular que microscópicamente se asemeja a un anillo, de allí su nomenclatura r (del inglés ring, que significa anillo). Tiene una incidencia de 1/40.000 nacidos vivos y hasta la fecha se han reportado aproximadamente entre 80 a 100 casos a nivel mundial sin embargo sólo existen alrededor de nueve reportes de r(18) en mosaico, aislado o asociado con otras alteraciones cromosómicas. A continuación, se presenta el caso de una paciente pediátrica con Síndrome del Anillo del cromosoma 18 estudiado y diagnosticado en la Unidad de Genética Médica de la Universidad Centroccidental Lisandro Alvarado en Barquisimeto, Venezuela, con la correspondiente revisión de la literatura relacionada con este síndrome(AU)

Chromosome 18 Ring Syndrome (18 [(r) 18]) is a chromosomal disorder that is included among the unbalanced structural anomalies in which chromosome 18 has a ring form which results from the simultaneous loss of both terminal segments of the short and long arms with the subsequent fusion of their ends forming a circular structure that microscopically resembles a ring, hence its nomenclature r (of the English ring, which means ring).18r Syndrome has an incidence of 1/40,000 live births; to date approximately 80-100 cases worldwide have been reported. There are only about nine reports of r(18) in mosaic, isolated or associated with other chromosomal alterations. We present a case of a pediatric patient with Chromosome 18 Ring Syndrome, evaluated and diagnosed in the Unidad de Genética Médica of the Universidad Centroccidental Lisandro Alvarado in Barquisimeto, Venezuela with the corresponding review of the literature(AU)

Clinical and genetic features of ring chromosome 13 syndrome: an analysis of one case / 中国当代儿科杂志

A girl aged 5 months was admitted due to developmental delay. Physical examination showed delayed physical development, unusual facies (microcephalus, hypertelorism, low-set ears, wide nasal bridge, and short philtrum), and an absence of the labium minus at one side. The peripheral blood karyotype was 46,XX,r(13)(p11q33)[82]/45,XX,-13[10]/46,XX,r(13;13)(p11q33;p11q33)[8], and array-based comparative genomic hybridization showed an 87.5 Mb duplication in 13q11q33.2 region and an 8.2 Mb deletion in 13q33.2q34 region. Fluorescence in situ hybridization showed terminal depletion of the long arm of the ring chromosome 13. The girl was diagnosed with ring 13 syndrome. This syndrome has various clinical phenotypes and is closely associated with the amount and site of the loss of genetic material in chromosomal band and different rates of chimerism.

Detection of a patient with ring chromosome 15 by low-coverage massively parallel copy number variation sequencing / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the genetic cause for a child with developmental delay.</p><p><b>METHODS</b>The karotypes of the child and her parents were analyzed with G-banding analysis. Their genome DNA was analyzed with low-coverage massively parallel copy number variation sequencing (CNV-seq) and verified by single nucleotide polymorphism array (SNP-array).</p><p><b>RESULTS</b>The karyotype of the child was ascertained as 46,XX,r(15)(p13q26.3), while both parents showed a normal karyotype. CNV-seq and SNP-array have identified a de novo 15q26.2-q26.3 deletion in the child with a size of approximately 3.60 Mb.</p><p><b>CONCLUSION</b>The abnormal phenotype of the patient carrying the ring chromosome 15 may be attributed to the presence of the 15q26.2-q26.3 microdeletion. The deletion and haploinsufficiency of the IGF1R gene probably underlie the main clinical features of the patient.</p>

Molecular cytogenetic analysis of a case with ring chromosome 3 syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the genetic cause for a child with developmental delay and congenital heart disease through molecular cytogenetic analysis.</p><p><b>METHODS</b>G-banded karyotyping and chromosomal microarray analysis (CMA) were performed for the patient and his parents.</p><p><b>RESULTS</b>The proband's karyotype was detected as ring chromosome 3, and a 3q26.3-25.3 deletion encompassing 45 genes has been found with CMA. Testing of both parents was normal.</p><p><b>CONCLUSION</b>Clinical phenotype of the patient with ring chromosome 3 mainly depends on the involved genes. It is necessary to combine CMA and karyotyping for the diagnosis of ring chromosome, as CMA can provide more accurate information for variations of the genome.</p>

Analysis of genetics mechanism for the phenotypic diversity in a patient carrying a rare ring chromosome 9 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the genetics mechanism for the phenotypic variability in a patient carrying a rare ring chromosome 9.</p><p><b>METHODS</b>The karyotype of the patient was analyzed with cytogenetics method. Presence of sex chromosome was confirmed with fluorescence in situ hybridization. The SRY gene was subjected to PCR amplification and direct sequencing. Potential deletion and duplication were detected with array-based comparative genomic hybridization (array-CGH).</p><p><b>RESULTS</b>The karyotype of the patient has comprised 6 types of cell lines containing a ring chromosome 9. The SRY gene sequence was normal. By array-CGH, the patient has carried a hemizygous deletion at 9p24.3-p23 (174 201-9 721 761) encompassing 30 genes from Online Mendelian Inheritance in Man.</p><p><b>CONCLUSION</b>The phenotypic variability of the 9p deletion syndrome in conjunct with ring chromosome 9 may be attributable to multiple factors including loss of chromosomal material, insufficient dosage of genes, instability of ring chromosome, and pattern of inheritance.</p>

Genetic diagnosis and analysis for two cases of ring chromosome 22 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To confirm the genetic diagnosis of two patients with ring chromosome 22 syndrome and investigate the mechanism underlying the formation of r(22) and potential genetic causes for the clinical phenotypes.</p><p><b>METHODS</b>Cytogenetic and molecular analyses using standard G-banding, fluorescence in situ hybridization and single nucleotide polymorphism array (SNP array) were performed.</p><p><b>RESULTS</b>For case 1, the karyotype was 46,XY,r(22)(p11q13). SNP array has identified a 7.0 Mb heterozygous deletion at 22q13.2q13.33. For case 2, the karyotype was 46,XY,r(22)(p11q13)[84]/45,XY,-22[6]; SNP array has detected a heterozygous microdeletion of 1.6 Mb at 22q13.33.</p><p><b>CONCLUSION</b>With combined application of genetic testing, 2 cases of r(22) syndrome were diagnosed, which has improved the understanding of the genotype-phenotype correlation of r(22).</p>

Caracterización citogenética y molecular de una paciente ecuatoriana con cromosoma 4 en anillo: análisis clínico comparativo con 37 casos internacionales / Cytogenetic and molecular characterization of a Ecuadorian patient with ring chromosome 4: comparative clinical analysis with 37 international cases

Los cromosomas en anillo son alteraciones genéticas muy inusuales, consecuencia de deleciones en las regiones terminales y de la unión de los extremos expuestos del cromosoma afectado. En un cromosoma 4 en anillo las regiones que con más frecuencia se afectan son 4p16.3 del brazo corto y 4q35.2 del brazo largo. Sujeto y métodos Se presenta el caso de una paciente con cromosoma 4 en anillo diagnosticado cuando tenía diez días de edad. Al examen clínico presentó dismorfogénesis importante: frente plana, nariz puntiforme, implantación baja de pabellones auriculares, clinodactilia del quinto dedo, microcefalia, micrognatia, un orifcio en la región lumbosacra, estatura baja y retardo mental leve. A los 10 años de edad se le realizó una evaluación citogenética con técnicas más modernas: hibridación in situ fluorescente (FISH) y mapeo genético por arrays de ADN. El fenotipo de la paciente fue comparado con 37 casos reportados en la literatura internacional. Resultados En el análisis clínico de la paciente y los 37 casos internacionales se encontró alrededor de 41 características clínicas diferentes y variables en cada sujeto. Las más frecuentes fueron retraso en el crecimiento (78%), microcefalia (67%), retardo mental (62%), bajo peso al nacer (48%), clinodactilia del quinto dedo (37%), micrognatia (29%), hipertelorismo (21%) y alguna cardiopatía (18%). El estudio citogenético de la paciente a los diez días de edad mostró un cariotipo en mosaico 46,XX/46,XX,r(4) con anillo del cromosoma 4 en el 80% de las metafases. A los diez años de edad se encontró r(4) en el 90% de las células. El análisis por FISH reveló un cariotipo 46,XX,r(4).ish r(4)(p16.3q35.2) (492870-793359-,190183811-190408149-). Los arrays evidenciaron las regiones de pérdida de los brazos cortos y largos del cromosoma 4 involucrados en la formación del anillo. Los genes que con seguridad inciden en el fenotipo de la paciente en estudio son LETM1, WHSC1, WHSC2, MIR943, TACC3, IDUA, C4orf48 para retardo mental; LETM1 y WHSC1 para microcefalia y KIAA1530 para retraso en el crecimiento.

Ring chromosomes are rare chromosomal structure abnormalities; they are formed when a chromosomal deletion leads to the fusion of both ends of the chromosome. The most frequent altered regions in ring chromosome 4 are 4p16.3 in short arm and 4q35.2 in long arm. Subject and methods Here we report a 10 days old female patient whose frst cytogenetic diagnosis showed a ring chromosome 4. Clinical examination showed congenital abnormalities including flattened forehead, prominent nose, low set ears, clinodactyly of the ffth fnger, microcephaly, micrognathia, small sacrococcygeal dimple, short stature and mild mental retardation. At the aged of ten fluorescence in situ hybridization (FISH) and DNA microarrays were performed. Finally, patient phenotype was compared with other 37 cases reported in the literature. Results The clinical analysis between the patient and the 37 cases reported showed about 41 different clinical features that vary between each individual. The most frequent features were growth retardation (78%), microcephaly (67%), mental retardation (62%), short stature at birth (48%), clinodactyly of the ffth fnger (37%), micrognathia (29%), hypertelorism (21%) and some type of cardiopathy (18%). Chromosome analysis of the patient at 10 days old appeared as a chromosomal mosaicism 46,XX/46,XX,r(4), with ring chromosome 4 in 80% of the metaphases analyzed. At 10 years old of the patient it was observed r(4) in 90% of the cells. FISH analysis showed a karyotype 46,XX,r(4).ish r(4)(p16.3q35.2) (492870-793359-,190183811-190408149-). The arrays showed deleted regions at the short and long arms of chromosome 4 involved in the formation of ring chromosome. The genes that are manifested in the patient phenotype are LETM1, WHSC1, WHSC2, MIR943, TACC3, IDUA, C4orf48 for mental retardation; LETM1 y WHSC1 for microcephaly and KIAA1530 for growth retardation.

Analysis of a infertile female with ring 21 chromosome using combined techniques / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate clinical phenotype and genetic characteristics of a 30-year-old infertile female carrying a mosaic ring 21 chromosome.</p><p><b>METHODS</b>A combination of techniques including G-banding, C-banding, fluorescence in situ hybridization (FISH) and SNP array were performed to investigate the breaking point of the r(21).</p><p><b>RESULTS</b>The karyotype of the patient was mos 46,XX,r(21)[166]/46, XX,der(21)[60]/45, XX, -21[20]/46, XX,dic r(21)[4].ish del(21)(q22.2?)(21qter-, AML1+, D21S259/D21S341/D21S342+). arr 21q22.3(43 457 934-48 093 361) × 1, 21q22.2q22.3(40 218 429-43 457 934)× 1-2. The karyotypes of her parents were both normal.</p><p><b>CONCLUSION</b>Clinical phenotypes of patients carrying a ring 21 mainly depends on the percentage of abnormal cells and the deleted chromosomal fragment. The small uterus and oligomenorrhea in our patient may be attributed to the mosaic ring 21 chromosome.</p>

Atypical teratoid rhabdoid brain tumor in an infant with ring chromosome 22 / 소아과

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 (5.6 cmx5.0 cmx7.6 cm) in the cerebellar vermis, which was detected in the brain via magnetic resonance imaging.

A Case of Ring Chromosome 14 Syndrome Presenting with Intractable Epilepsy / 대한간질학회지

Ring chromosome 14 syndrome is a rare cytogenetic disorder characterized by typical facial appearance, developmental delay, and intractable epilepsy. There have been about 50 reported cases in the world and one case in Korea. Epilepsy is the most common and serious neurologic comorbidity of the syndrome and it typically begins at early ages and frequently becomes intractable. We report a girl with ring chromosome 14 syndrome who showed early onset intractable epilepsy with repetitive episodes of clustering seizures. We describe the case and the result of long term follow-up for the epilepsy. The early suspicion of the syndrome and prompt management for seizures are necessary for the favorable prognosis.