Genetic analysis of a case of B-acute lymphoblastic leukaemia with double Philadelphia chromosomes and double derivative chromosome 9s / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a rare case of acute B-lymphocytic leukemia (B-ALL) with double Philadelphia chromosomes (Ph) and double derivative chromosome 9s [der(9)].@*METHODS@#A patient with double Ph and double der(9) B-ALL who presented at Shanghai Zhaxin Intergrated Traditional Chinese and Western Medicine Hospital in June 2020 was selected as the subject. Bone marrow morphology, flow cytometry, G-banding karyotyping, fluorescence in situ hybridization (FISH), genetic testing and chromosomal microarray analysis (CMA) were used to analyze bone marrow samples from the patient at various stages.@*RESULTS@#At initial diagnosis, the patient's bone marrow morphology and flow immunotyping have both supported the diagnosis of B-ALL. G-banded karyotyping of the patient indicated double Ph, in addition with hyperdiploid chromosomes involving translocations between chromosomes 9 and 22. BCR-ABL1 fusion gene was positive. Genetic testing at the time of recurrence revealed presence of a heterozyous c.944C>T variant in the kinase region of the ABL1 gene. FISH showed a signal for ABL1-BCR fusion on both chromosome 9s. CMA showed that the mosaicism homozygosity ratio of chromosome 9 was about 40%, and the mosaicism duplication ratio of chromosome 22 was about 43%.@*CONCLUSION@#Since both der(9) homologs were seen in 40% of cells, the possible mechanism for the double der(9) in this patient may be similar to that of double Ph, which might have resulted from non-disjunction during mitosis in the Ph chromosome-positive cell clone.

Clinical and genetic analysis of three children patients with Kleefstra syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of three children with unexplained developmental delay/intellectual disability (DD/ID).@*METHODS@#Peripheral blood samples were collected from the patients and subjected to chromosomal microarray analysis (CMA).@*RESULTS@#Patient 1 was found to harbor a 190 kb deletion at 9q34.3, which encompassed most of EHMT1 (OMIM 607001), the key gene for Kleefstra syndrome (OMIM 610253). Patients 2 and 3 were siblings. CMA showed that they have shared four chromosomal copy number variations (CNVs) including a deletion at 9q34.3 which spanned 154 kb and 149 kb, respectively, and encompassed the EHMT1 and CACNA1B (OMIM 601012) genes. The remaining 3 CNVs were predicted to be with no clinical significance.@*CONCLUSION@#Microdeletions at 9q33.4 probably underlay the pathogenesis of DD/ID in the three children, for which EHMT1 may be the key gene.

Genetic analysis of three patients with Kleefstra syndrome / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical and genetic features of three patient diagnosed with Kleefstra syndrome.@*METHODS@#Whole exome sequencing (WES) was carried out for the probands and their parents. Suspected variants were validated by Sanger sequencing. Copy number variations (CNV) were detected by CNV-seq and validated by real-time PCR.@*RESULTS@#Proband 1 was found to carry a de novo heterogeneous variant (c.823+1G>T) of the EHMT1 gene, which may affect its expression. Based on the guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic (PVS1+PS2+PM2). Proband 2 was found to carry a de novo missense variant c.439C>G (p.L147V) of the EHMT1 gene, which was predicted to be likely pathogenic (PS2+PM1+PM2+PP3). Proband 3 was found to carry a heterozygous 520 kb deletion at 9q34.3 by CNV-seq. The deletion has encompassed the whole of the EHMT1 gene. Real-time PCR has detected no CNV of this region in her parents.@*CONCLUSION@#Variants of the EHMT1 gene probably underlay the disease in these patients. Genetic testing has provided a basis for their clinical diagnosis.

Genetic analysis of a family with 9q34.3 microdeletion and microduplication caused by abnormal chromosome balance structure / 中华医学遗传学杂志

OBJECTIVE@#To perform prenatal diagnosis, pedigree analysis, and genetic counseling of a pregnant woman who gave birth to a child with Kleefstra syndrome.@*METHODS@#Karyotype analysis, chromosomal microarray analysis (CMA), multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH) were used of peripheral blood and amniotic fluid to find causes. Recurrence risk assessment was performed later.@*RESULTS@#The amniotic fluid sample showed a 9q34.3 microduplication of arr (hg19) 9q34.3 (140 168 806-141 020 389)× 3, which overlapped the 9q34.3 microdeletion region of proband. The pregnant woman was detected with a balanced translocation of ish, t(9;17)(9q34.3; qter) (9p+; 17p+,9q+, 17q+). No other abnormal results were found in the family.@*CONCLUSION@#Offspring who share the same chromosome segment deletion or duplication are always from parent who carries balanced chromosomal structural aberration.

Trisomía 9p: Una breve descripción clínica, diagnóstica y terapéutica / Trisomy 9p: A brief clinical, diagnostic and therapeutic description

La trisomía del 9p se caracteriza por la duplicación de todo o de algún segmento del brazo corto del cromosoma 9. Es una de las anomalías autosómicas estructurales más frecuentes en recién nacidos. Esta región es relativamente pobre en genes, por lo que puede ser más compatible con la supervivencia. Se caracteriza por presentar retraso del crecimiento, psicomotor y mental, dismorfias cráneo-faciales, alteraciones esqueléticas, así como anomalías en el sistema nervioso central, cardiopatías congénitas y alteraciones renales en menor frecuencia. Para realizar el diagnóstico, debe desarrollarse el estudio citogenético mediante la técnica de banda G, y, si está disponible, se recomienda la hibridación por fluorescencia in situ, complementada por la hibridación genómica comparativa, para la mejor comprensión de la correlación genotipo-fenotipo. La evaluación debe ser interdisciplinaria, en la que se incluya un oportuno asesoramiento genético familiar y, con ello, las opciones terapéuticas disponibles y de forma precoz.

Trisomy 9p is characterized by the partial or complete duplication of the short arm of chromosome 9. It is one of the most common autosomal structural abnormalities in newborn infants. This is a relatively poor gene region, so it may be more compatible with survival. It is characterized by delayed mental and psychomotor growth, craniofacial dysmorphisms, skeletal alterations, central nervous system abnormalities, congenital heart disease, and, to a lesser extent, kidney disorders. To establish a diagnosis, it is necessary to perform a cytogenetic study with G bands and, if available, fluorescence in situ hybridization complemented with comparative genomic hybridization for a better understanding of the genotype-phenotype correlation. Assessment should be interdisciplinary and encompassing a timely family genetic counseling, together with available therapeutic options in an early manner.

Analysis of a pedigree with partial trisomy 9 and partial monosomy 13 derived from a maternal balanced t(9;13) translocation / 中华医学遗传学杂志

OBJECTIVE@#To determine the nature and origin of aberrant chromosomes in a child with multiple anomalies and psychomotor retardation.@*METHODS@#Routine G-banding was carried out to analyze the karyotypes of the patient and his parents, and next generation sequencing for copy number variations (CNV-seq) was used for the fine mapping of the aberrant chromosomal regions.@*RESULTS@#The proband and his uncle exhibited psychomotor retardation, craniofacial malformation, infantile external genitalia, and concealed penis. Cytogenetic analysis indicated that the child has a 46,XYqh+,+(9),t(9;13)(q13;q12),pat,-13 karyotype. His uncle was XYqh+,+(9),t(9;13)(q13;q12)mat,-13, his father was 46,XYqh+,t(9;13)(q13;q12)mat, his grandmother was 46,XX,t(9;13)(q13;q12), and his grandfather was 46,XYqh+. The result of CNV-seq assay for the child was 46,XY,+9p(pter-p13.2,-40 Mb×3). No deletion was detected.@*CONCLUSION@#The partial trisomy 9 and partial monosomy 13 probably underlie the phenotypic abnormalities in the child. Combined chromosomal karyotyping and DNA sequencing can facilitate delineation of the nature and origin of the aberrant chromosomes.

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.

Monosomía 9p24 secundaria a translocación (2; 9) en dos pacientes no relacionadas / Monosomy 9p24 in two non-related patients as result of a translocation (2; 9)

En pacientes con malformaciones congénitas y retraso del desarrollo psicomotor, deben descartarse cromosomopatías. Las más frecuentes son las translocaciones recíprocas balanceadas, presentes en 1:500 recién nacidos vivos. Por lo general, los portadores tienen fenotipo normal, aunque, ocasionalmente, presentan infertilidad, abortos o hijos con malformaciones. La translocación balanceada entre los cromosomas 2 y 9 puede originar descendencia con monosomías y trisomías de estos cromosomas. La monosomía del brazo corto del cromosoma 9 puede presentarse con trigonocefalia, dismorfias faciales, anomalías genitales y retraso del desarrollo psicomotor. En este trabajo, se revisaron las alteraciones de los cromosomas 2 y/o 9 en los cariotipos realizados en nuestra Institución en 2005-2014. Se presentan dos pacientes con monosomía 9p asociada a translocación (2;9). Las pacientes comparten datos de monosomía 9p24-pter; la correlación genotipo-fenotipo es compleja por el tamaño de los segmentos involucrados. Se resalta la importancia del diagnóstico cromosómico para el asesoramiento genético.

In patients with malformations and delayed psychomotor development it is important to discard chromosomopathies. Balanced reciprocal translocations are the most frequent chromosomopathies present in 1:500 live newborns. In general, carriers have normal phenotype, but they may have infertility, abortions or children with congenital malformations. The reciprocal translocation between chromosomes 2 and 9 can lead to offspring with monosomies and trisomies of these chromosomes. Short arm monosomy of chromosome 9 may present delayed psychomotor development, trigonocephaly, facial dysmorphia and genital abnormalities. We reviewed GTG karyotype records from our Institution to identify cases with chromosomes 2 and/or 9 alterations from 2005 to 2014. We describe two cases with monosomy 9p secondary to a translocation between chromosomes 2 and 9. The patients share features of monosomy 9p24-pter, however the genotype-phenotype correlation is complex due to the extension of the involved segments. We emphasize the importance of chromosomal diagnosis to offer genetic assessment.

Diagnosis of a case with partial 9p trisomy by next generation sequencing / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic cause for a child featuring growth and mental retardation.@*METHODS@#Following conventional karyotyping analysis of the trio family, next generation sequencing (NGS) was carried out to explore the origin of the supernumerary marker chromosome. Fluorescence in situ hybridization (FISH) was used to confirm the result.@*RESULTS@#The karyotypes of both parents were normal, while the proband was found to be 47,XX,+mar. NGS showed that the supernumerary marker has originated from chromosome 9p13.1p24.3 with a size of 39.77 Mb. FISH has confirmed the above finding.@*CONCLUSION@#The 9p13.1-p24.3 trisomy probably underlies the abnormal phenotypes of the child. Cytogenetic analysis combined with NGS and FISH can provide accurate diagnosis for such disorders.

The incidence of atypical patterns of BCR-ABL1 rearrangement and molecular-cytogenetic response to tyrosine kinase inhibitor therapy in newly diagnosed cases with chronic myeloid leukemia (CML)

BACKGROUND: To analyze the frequency of atypical fluorescence in situ hybridization signal patterns and estimate the complete cytogenetic response (CCyR) and major molecular response (MMR) during 12 months of tyrosine kinase inhibitor therapy in patients with newly diagnosed chronic myeloid leukemia. METHODS: The study included bone marrow and peripheral blood samples from 122 patients with newly diagnosed chronic myeloid leukemia. Detection of the breakpoint cluster region—Abelson fusion gene (BCR-ABL1) was performed using fluorescence in situ hybridization with a dual-color dual-fusion translocation probe, and MMR analysis was performed using the real-time quantitative polymerase chain reaction method. RESULTS: Variant translocation was determined in 10 samples and a deletion on the derivative chromosome 9 (del/der(9)) was found in 20 samples. The rates of CCyR and MMR were similar between patients with reciprocal translocation, variant translocation, deletion of derivative BCR, or ABL1-BCR fusion gene. The Kaplan-Meier test did not show any significant differences in the rates of CCyR and MMR among those groups of patients. CONCLUSION: The frequencies of variant translocation and del/der(9) in the present study agree with the results of other studies performed worldwide. No differences were observed in the rates of CCyR and MMR between patients with atypical patterns and reciprocal translocation.

Síndrome de Gorlin-Goltz, actualización: a propósito de un caso en el Hospital Infantil de Morelia / Gorlin-Goltz syndrome update: apropos of a case at the Morelia Children Hospital

Este síndrome fue escrito en 1960 por Robert J Gorlin, patólogo bucalinvestigador formado en Minnesota y por Robert W Goltz, dermatólogo. Es un trastorno autosómico dominante ocasionado por el gen Patched 1 (PTCH1) que se ubica en el cromosoma 9q223, caracterizado por defectos en el desarrollo y alta predisposición al cáncer. La prevalencia es de 1/56,000 y 1/221,000 pacientes. El padecimiento se caracteriza por desarrollo de carcinomas basocelulares, queratoquistes odontogénicos y malformaciones esqueletales. Debido a su alta predisposición al desarrollo de carcinomas basocelulares agresivos, debe diagnosticarse temprana y oportunamente para un pronóstico favorable.

Robert Gorlin a mouth researcher trained pathologist Minnesota andRobert Goltz a dermatologist described this syndrome in 1960. It is anautosomal dominant disorder, caused by the Patched 1 gene (PTCH1)located on chromosome 9q223 characterized by developmental defectsand a high predisposition to cancer. The incidence is 1/56,000 and1/221,000 patients. The condition is characterized by the developmentof basal cell carcinomas, odontogenic keratocystic and skeletalmalformations. Due to its high predisposition to the development ofaggressive basal cell carcinomas should be early and timely diagnosisfor a favorable prognosis.

Patient With Delayed Development Resulting From De Novo Duplication of 7q36.1-q36.3 and Deletion of 9p24.3

Patients with a duplication from 7q36 to the terminus or a deletion of 9p24 have been reported, whereas those harboring both mutations have not. Here, we report a patient with simultaneous de novo 7q36.1-q36.3 duplication and 9p24.3 deletion. A 6-year-old boy presented with speech developmental delay, microcephaly, and dysmorphic features, including a long face and small nose. Chromosome and array comparative genomic hybridization analyses revealed 46,XY,dup(7)(q36.1-q36.3) and del(9)(p24.3). The sizes of the duplication and deletion were 9.9 Mb and 1.9 Mb, respectively. The duplication of chromosome 7 contained 68 known genes, of which 3 are related with entries in the Developmental Disorders Genotype-to-Phenotype (DDG2P) database. The deletion of chromosome 9 contained 6 known genes, of which 2 are in the DDG2P database. We investigated the genotype and phenotype in this patient, and reviewed the relevant literatures for possible clinical presentation in these variations.

A Case of Partial Short Arm Deletion in Chromosome 9 with Inguinal Hernia, Testicular Cystic Lesion, and Arthrogryposis Multiplex Congenita

Chromosome 9p syndrome is a rare chromosomal abnormality caused by a partial deletion in chromosome 9. It was first described in 1973 by Alfi et al., and has since been shown to have diverse clinical phenotypes. Here, we reported a case of a male infant with joint contracture of the extremities, dysmorphic face, inguinal hernia, and testicular cystic masses. Chromosomal analysis revealed a terminal deletion at the short arm of chromosome 9. The major clinical features of the 9p deletion syndrome are trigonocephaly, small palpebral fissures, a flat nasal bridge, and mental retardation. To the best of our knowledge, this is the first reported case of a patient with 9p24 deletion presenting with arthrogryposis multiplex congenita.

Analysis of isodicentric Ph chromosomes in chronic myeloid leukemia blast crisis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the genetic and clinical characteristics of isodicentric Ph chromosomes [idic(Ph)] in lymphoid blast crisis of chronic myeloid leukemia (CML-BLC).</p><p><b>METHODS</b>Bone marrow aspirates of 2 patients with CML-BLC were analyzed by R banding after 24 hours of culturing. Genomic copy number variations (CNV) were analyzed by single nucleotide polymorphism array (SNP array) in case 1. The results were confirmed with fluorescence in situ hybridization (FISH). Variations of acute lymphoblastic leukemia-related genes including CDKN2A/AB and PAX5 were detected by multiplex ligation-dependent probe amplication (MLPA).</p><p><b>RESULTS</b>Deletions and duplications on derivative chromosome 9 detected by FISH were confirmed by SNP array analysis. The distances between the BCR/ABL fusion signals on the idic(Ph) chromosomes in the two patients have differed greatly. The idic(Ph) in the second patient was supposed to be formed by two Ph chromosomes joined at their q terminals, where as the idic(Ph) in the first patient have been shown to be fused at the satellite regions of their p arms.</p><p><b>CONCLUSION</b>The idic(Ph) chromosomes presented in CML-BLC may predict resistance to Imatinib and response to Dasatinib.</p>

Clinical and genetic analysis of a boy with 9q34.3 microdeletion syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the origin of chromosomal aberration in a boy with mental retardation and multiple congenital malformations.</p><p><b>METHODS</b>The karotypes of the proband and his parents were analyzed with conventional G-banding. Their genomic DNA was analyzed with array comparative genomic hybridization (aCGH).</p><p><b>RESULTS</b>No karyotypic abnormality was detected in the proband and his parents. aCGH has identified a de novo 405 kb deletion at 9q34.3 in the proband, which encompassed the EHMT1 gene and part of CACNA1B gene.</p><p><b>CONCLUSION</b>The de novo 9q34.3 deletion probably underlies the mental retardation and development delay in the boy. EHMT1 may be one of the key genes responsible for 9q34.3 microdeletion syndrome.</p>

Genetic study of a fetus with 9p direct duplication deletion syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To use next generation sequencing (NGS) to identify unknown abnormality of chromosome 9 in a fetus and explore its mechanism.</p><p><b>METHODS</b>A pregnant woman with abnormal fetal ultrasound finding underwent amniocentesis for G-banded chromosomal analysis. Karyotyping was also performed on peripheral blood samples derived from its parents. Fetal blood sample was obtained for NGS testing to identify abnormality unrecognized by karyotyping.</p><p><b>RESULTS</b>Analysis of amniocytes has revealed a 46,XX,der(9)(?::p21 to qter) karyotype, while both parents had a normal karyotype. NGS analysis of the fetus revealed a 20.67 Mb duplication (4 454 279-25 126 275) at 9p21.3p24.2, which overlapped with that of the 9p duplication syndrome, and a 4.43 Mb deletion at 9p24.2p24.3 (10 001-4 442 364), which partially overlapped with that of 9p deletion syndrome and 46,XY sex reversal 4 region. Comparison of the sequencing data with reference genome database indicated direct duplication of 9p21.3p24.2, which was also supported by review of the morphology of chromosome 9p. Therefore, the karyotype of the fetus was verified to be 46,XX,der(9) dir dup(9)(p21.3p24.2), del(9)(p24.2p24.3).</p><p><b>CONCLUSION</b>Combined G-banded karyotyping and NGS can identify dir dup del(9p) with accuracy. Delineation of the mechanism of dir dup del(9p) and its genotype-phenotype correlation may facilitate genetic counseling and estimation of recurrence risk.</p>

A Case of Chronic Myeloid Leukemia With Rare Variant ETV6/ABL1 Rearrangement

No abstract available.

‘Hummingbird’ Sign in a Patient with Guam Parkinsonism-Dementia Complex

We present a case of a 71-year-old male Chamorro patient from Guam who presented with progressive supranuclear palsy (PSP)-Richardson’s syndrome. Considering his strong family history of parkinsonism and a PSP phenotype, he was clinically diagnosed with Guam parkinsonism-dementia complex (PDC). Magnetic resonance imaging (MRI) of the brain revealed prominent midbrain atrophy with preserved pontine volume, forming the ‘hummingbird’ sign, which has not been described before in Guam PDC. Molecular analysis of the chromosome 9 open reading frame 72 gene (C9orf72) showed only 6 GGGGCC repeats. We discuss the clinico-pathological similarities and differences between PSP and Guam PDC, and highlight the topography of neuropathological changes seen in Guam PDC to explain the appearance of the ‘hummingbird’ sign on MRI.

B-cell Acute Lymphoblastic Leukemia With t(9;22)(q34;q11) Translocation and Clonal Divergence Through ider(22) Chromosome and t(13;17)(q14;q25) Translocation

No abstract available.