Terminal deletion of the short arm of chromosome 6 (6P25 3P 243): a literature review and case report of a Brazilian child / Deleção terminal do braço curto do cromossomo 6 (6p25 3p 243): uma revisão de literatura e relato de caso de uma criança brasileira

Introduction: Deletion syndromes are rare events in clinical practice. A chromosomal deletion occurs when seg-ments of genetic information are missing on a particular chromosome or more. The absence of some genes implies varied phenotypes, which detailed explanation is not fully elucidated yet. Objective: Report the case of a child with a terminal segment deletion of 8,9 Mb on the short arm of chromosome 6 (in 6p25.3p24.3) Methods: This case report was approved by the Ethics and Research Committee of the institution. For its preparation, the exam data provided by the patient's family were added from prenatal to early childhood and the discussion with professionals related to the case. Results: B.A.G., a two-year-old female child, the only daughter of non-consanguineous par-ents, no family history of similar diseases. She was born by premature cesarean section (GA: 35 weeks), presenting Dandy-Walker malformation, Fallot tetralogy, head circumference in the 97th percentile, and syndromic facies, with hypertelorism, low implantation of the ears, and opacity of both lenses. Conclusion: Deletions on chromosome 6 are a very rare genetic alteration. Until 2004, there were only 43 cases in the medical literature, excluding ring chromosome 6 anomalie31. Regarding the terminal deletions of the short arm, this case specifically - 6p24pter - was associated with developmental delay, brain malformations, abnormalities in the anterior chamber of the eye, hearing loss, and abnormalities in the ear, micrognathia, and heart diseases (AU)

Introdução: As síndromes de deleção são eventos raros na prática clínica. A deleção cromossômica ocorre quando segmentos de informação genética são perdidos em um ou mais cromossomos. A ausência de alguns genes implica em fenótipos variados, cuja explicação detalhada ainda não está totalmente elucidada. Objetivo: Relatar o caso de uma criança com deleção de segmento terminal de 8,9 Mb do braço curto do cromossomo 6 (em 6p25.3p24.3) Métodos: Esse relato de caso foi aprovado pelo Comitê de Ética e Pesquisa da Instituição. Para sua elaboração, foram adicionados os dados de exames fornecidos pela família do paciente desde o pré-natal até a primeira infância e a discussão com profissionais relacionados ao caso. Descrição do Caso: B.A.G., criança de dois anos, sexo femi-nino, filha única de pais não consanguíneos, sem antecedentes na família de doenças similares. Nasceu por cesárea prematura (IG 35 semanas), apresentando Síndrome de Dandy-Walker, tetralogia de Fallot, perímetro cefálico no percentil 97 e fácie sindrômica, com hipertelorismo, baixa implantação das orelhas e opacidades do cristalino bi-lateralmente. Conclusão: As deleções no cromossomo 6 são alterações genéticas de grande raridade. Até 2004, existiam apenas 43 casos na literatura médica, excluindo a anomalia do cromossomo 6 em anal 31. No que se refere às deleções terminais do braço curto, a do caso em questão - 6p24-pter - foram associadas o atraso no desenvol-vimento, malformações cerebrais, anormalidades na câmara anterior do olho, perda auditiva, anormalidades no ouvido, micrognatia e cardiopatias (AU)

Investigação Citogenômica de Crianças com Doença Cardíaca Congênita: Experiência de um Centro no Brasil / Cytogenomics Investigation of Infants with Congenital Heart Disease: Experience of a Brazilian Center

Resumo Fundamento Algumas síndromes têm características específicas e facilmente reconhecíveis, enquanto outras podem ser mais complexas de se identificar e podem apresentar diferentes manifestações fenotípicas, por exemplo. Um diagnóstico etiológico é importante para entender a natureza da doença, para estabelecer o prognóstico e para começar o tratamento, permitindo a inclusão de pacientes na sociedade e reduzindo o custo financeiro dessas doenças. Objetivo A proposta inicial deste estudo foi a triagem citogenética para detectar a síndrome de deleção 22q11.2 (SD22q11.2) em recém-nascidos e crianças com doença cardíaca congênita utilizando a técnica da amplificação multiplex de sondas dependente de ligação (MLPA). Assim, por meio da pesquisa, outras mudanças genômicas foram identificadas nesses pacientes cardíacos. Nosso objetivo se estendeu a investigar essas outras mudanças citogenéticas. Métodos Investigamos 118 recém-nascidos com doenças cardíacas congênitas nascidos consecutivamente durante um ano, utilizando a técnica da MLPA. Resultados A técnica da MLPA permitiu a detecção da SD22q11.2 em 10/118 pacientes (8,5%). Outras alterações genômicas foram identificadas em 6/118 pacientes (5%): 1p36 del, 8p23 del (2 casos), 7q dup, 12 dup e 8q24 dup. Conclusão Este estudo ressalta a relevância da detecção de alterações genômicas que estão presentes em recém-nascidos e crianças com doenças cardíacas congênitas por meio de ferramentas citogenômicas.

Abstract Background Some syndromes have specific and easily recognizable features, while others may be more complex to identify and may present different phenotypic manifestations, for example. An etiological diagnosis is important to understand the nature of the disease, to establish the prognosis and to start the treatment, allowing the inclusion of patients in society and reducing the financial cost of such diseases. Objective The initial proposal of this study was cytogenetic screening for the detection of the 22q11.2 deletion syndrome in consecutive newborns and infants with congenital heart disease using the multiplex ligation-dependent probe amplification (MLPA) technique. Therefore, throughout our research, other genomic alterations were identified in these cardiac patients. Thus, our objective was extended to investigate these other cytogenetic alterations. Methods We investigated 118 neonates with congenital heart diseases born consecutively during one year using the MLPA technique. Results The MLPA technique allowed the detection of 22q11.2DS in 10/118 patients (8.5%). Other genomic alterations were also identified in 6/118 patients (5%): 1p36 del, 8p23 del (2 cases), 7q dup, 12 dup and 8q24 dup. Conclusion This study highlights the relevance of detecting genomic alterations that are present in newborns and infants with congenital cardiac diseases using cytogenomic tools.

Genetic research progress in branchio-oto syndrome/ branchio-oto-renal syndrome / 中南大学学报(医学版)

Branchio-oto syndrome (BOS)/branchio-oto-renal syndrome (BORS) is a kind of autosomal dominant heterogeneous disorder. These diseases are mainly characterized by hearing impairment and abnormal phenotype of ears, accompanied by renal malformation and branchial cleft anomalies including cyst or fistula, with an incidence of 1/40 000 in human population. Otic anormalies are one of the most obvious clinical manifestations of BOS/BORS, including deformities of external, middle, inner ears and hearing loss with conductive, sensorineural or mix, ranging from mild to profound loss. Temporal bone imaging could assist in the diagnosis of middle ear and inner ear malformations for clinicians. Multiple methods including direct sequencing combined with next generation sequencing (NGS), multiplex ligation-dependent probe amplification (MLPA), or array-based comparative genomic hybridization (aCGH) can effectively screen and identify pathogenic genes and/or variation types of BOS/BORS. About 40% of patients with BOS/BORS carry aberrations of EYA1 gene which is the most important cause of BOS/BORS. A total of 240 kinds of pathogenic variations of EYA1 have been reported in different populations so far, including frameshift, nonsense, missense, aberrant splicing, deletion and complex rearrangements. Human Endogenous Retroviral sequences (HERVs) may play an important role in mediating EYA1 chromosomal fragment deletion mutations caused by non-allelic homologous recombination. EYA1 encodes a phosphatase-transactivator cooperated with transcription factors of SIX1, participates in cranial sensory neurogenesis and development of branchial arch-derived organs, then regulates the morphological and functional differentiation of the outer ear, middle ear and inner ear toward normal tissues. In addition, pathogenic mutations of SIX1 and SIX5 genes can also cause BOS/BORS. Variations of these genes mentioned above may cause disease by destroying the bindings between SIX1-EYA1, SIX5-EYA1 or SIX1-DNA. However, the role of SIX5 gene in the pathogenesis of BORS needs further verification.

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).

Clinical genetic analysis of an infant with 1q21.3-qter duplication and Xpter-p11 deletion caused by maternal balanced chromosomal translocation / 中华医学遗传学杂志

OBJECTIVE@#To investigate the clinical phenotype and genetic diagnosis of an infant featuring multiple hair and hyperbilirubinemia.@*METHODS@#Conventional G-banding analysis, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) for the patient were conducted, G-banding analyses of peripheral blood for the infant's parents were also performed.@*RESULTS@#We investigated an infant who carries a unbalanced, maternally inherited karyotype 46, X, der (X) t (X;1) (p11.22; q21.3) in which CMA and FISH analyses disclosed a 1q21.3q44 duplication of 93.03 Mb and Xp22.33p11.22 deletion of 54.53 Mb.@*CONCLUSION@#The phenotypes of this infant can probably be attributed to the 1q21.3q44 duplication and Xp22.33p11.22 deletion, which were maternally inherited.

Clinical characteristics and genetic analysis of a neonate with Smith-Magenis syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and genetic etiology for a neonate with Smith-Magenis syndrome (SMS).@*METHODS@#Copy number variation sequencing (CNV-seq) was applied to the neonate and his parents, and the genotype-phenotype correlation was analyzed.@*RESULTS@#On the second day after birth, the neonate had presented with pathological jaundice and immunodeficiency. Cranial MRI revealed ventricular enlargement and enlargement of cisterna magna. At 3 months, the infant has presented with square face, prominent forehead, deep-set eyes, hypertelorism, palpebral fissure upward and button noses. Genetic testing showed that he had carried a 2.9 Mb deletion in 17p11.2 region, seq[GRCh37] del(17)(p11.2)(chr17:16 836 379-19 880 992). The same deletion was not found in either parent.@*CONCLUSION@#SMS is mostly diagnosed in child and adulthood, but rarely in neonates. For neonates with SMS, the neurological and behavioral abnormalities have not been shown, but pathological jaundice, CNS abnormalities and immune deficiency may be the characteristics, which require attention of neonatal physicians.

Prenatal ultrasonographic manifestations and genetic analysis of eight fetuses with 16p11.2 microdeletions / 中华医学遗传学杂志

OBJECTIVE@#To analyze the intrauterine phenotype and genotype of eight fetuses carrying a 16p11.2 microdeletion.@*METHODS@#5100 fetuses undergoing routine prenatal diagnosis were subjected to single nucleotide polymorphism-based microarray (SNP-array) analysis. Fetuses harboring a 16p11.2 microdeletion were analyzed for their ultrasonographic characteristics.@*RESULTS@#Eight fetuses were found to harbor a microdeletion in the 16p11.2 region. Among these, six had a typical 500-600 kb deletion, while the remaining two had an atypical 220 kb deletion at the distal part of 16p11.2. Four fetuses showed vertebral malformations, two had mild left ventriculomegaly, one had hydrocephalus, and one had pulmonary valve stenosis with regurgitation. The parents of five fetuses have accepted pedigree verification, and the results confirmed that the 16p11.2 microdeletions carried by fetuses all had a de novo origin.@*CONCLUSION@#The intrauterine phenotypes of fetuses carrying a 16p11.2 microdeletion may be variable, and the deletion can be effectively detected with the SNP-array assay.

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 a case with 2q37 microdeletion syndrome / 中华医学遗传学杂志

OBJECTIVE@#To diagnose and fine map a deletion in chromosome region 2q37.@*METHODS@#G-banded chromosomal karyotyping, multiplex ligation-dependent probe amplification (MLPA), single nucleotide polymorphism array (SNP-array), and fluorescence in situ hybridization (FISH) were carried out in conjunct for the analysis.@*RESULTS@#The patient was found to have karyotype of 46,XY,del(2)(q3?), MLPA revealed one copy number of both CAPN10-3 and ATG4B-7 genes from the 2q37.3 region, Both parents were found to be normal upon chromosome karyotyping and MLPA. SNP-array has found a 9.7 Mb deletion in the 2q37.1.37.3 region. FISH analysis has confirmed there is a single copy for 2q37.3.@*CONCLUSION@#Combination of MLPA, FISH and SNP-array have enabled accurate diagnosis for the patient, and also provided more clues for the correlation of genotype with the phenotype of the disease, and a basis for genetic counseling.

Uleritema ofriógenes como entidad asociada al síndrome 18p- en un paciente pediátrico / Ulerythema ophryogenes as an entity associated with 18p- syndrome in a pediatric patient

El uleritema ofriógenes es un trastorno cutáneo benigno y poco frecuente que se presenta habitualmente en la infancia. Se caracteriza por pápulas foliculares eritematosas y queratósicas en el lateral de las cejas, que con el tiempo suelen evolucionar a alopecia cicatricial. Dicha entidad puede aparecer como manifestación clínica aislada o asociada a varios síndromes congénitos (18p-, Cornelia de Lange, Noonan y Rubinstein- Taybi, entre otros). Presentamos el caso de un paciente de 13 años con síndrome 18p- que consultó por lesiones puntiformes rugosas al tacto y pérdida de pelo en ambas cejas (uleritema ofriógenes), así como por hiperqueratosis pilar en brazos. Esta tríada, conocida como síndrome de Zouboulis, ha sido poco descrita en la literatura. Se considera que el reconocimiento del uleritema ofriógenes es de crucial importancia ya que, ante su presencia, debería realizarse una anamnesis y una exploración física exhaustivas en búsqueda de otras alteraciones que pudieran orientar a la existencia de un trastorno genético subyacente.

Ulerythema ophryogenes is a benign and rare skin disorder commonly presenting in childhood. It is characterized by erythematous and keratotic follicular papules located on the side of the eyebrows, and which over time tends to evolve into scarred alopecia. This entity may appear as an isolated clinical manifestation or associated with several congenital syndromes (18p-, Cornelia de Lange, Noonan, Rubinstein-Taybi, among others). We present a 13-year-old male with 18p- syndrome who consults for rough lesions and hair loss in both eyebrows (ulerythema ophryogenes), as well as for hyperkeatosis pilaris in both arms. This triad, known as Zouboulis syndrome, has been rarely reported in the literature. We consider that the recognition of ulerythema ophryogenes is of crucial importance since, in view of its presence, comprehensive anamnesis and physical examination should be performed in search of other alterations that could guide the existence of an underlying genetic disord

Pleomorphic Xanthoastrocytoma with Oligodendroglioma-Like Areas with Negative 1p19q Co-Deletion

The most common mixed glioma encountered in routine surgical practice is oligoastrocytoma (OA); however, its is currently considered a vanishing entity. The 2016 classification of the World Health Organization (WHO) discourages the diagnosis of tumors as mixed glioma. The recommendations are that diffuse gliomas, including those withmixed or ambiguous histological features, should be subjected tomolecular testing. Dual-genotype OAs are not yet a distinct entity or variant in the classification. We report a case ofmixed glioma: a pleomorphic xanthoastrocytoma (PXA)mixed with an oligodendroglioma. The immunohistochemistry (IHC) pattern of isocitrate dehydrogenase 1 (IDH1) negativity with retained nuclear expression of the alpha-thalassemia x-linked intellectual disability syndrome (ATRX) protein, and 1p19q co-deletion negativity in both the components enabled its identification as a mixed glioma rather than a collision tumor. To the best of our knowledge, the case herein presented is the fourth case of PXA with oligodendroglioma. Out of the other three reported cases, only one was of a collision tumor with a dual genotype, and the other two showed similar molecular signatures in both components. The present article discusses the histological, immunohistochemical and molecular features of the aforementioned case.

Prenatal diagnosis of a fetus with chromosome 18p deletion and duplication / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of chromosomal microarray analysis (CMA) to verify a fetus with partial 18p deletion signaled by non-invasive prenatal testing.@*METHODS@#G-banding chromosomal karyotyping analysis was carried out on amniotic fluid sample of the fetus and peripheral blood samples from the parents. Amniotic DNA was also subjected to CMA analysis. The fetus was also subjected to systematic ultrasound scan.@*RESULTS@#The fetus was found to have a karyotype of 46,XX,18p+. CMA has revealed a 5 Mb deletion at 18p11.32-p11.31, a 2.9 Mb duplication at 18p11.31-p11.23, and a 2.5 Mb duplication at 18p11.23-p11.22. No chromosomal aberration or microdeletion/microduplication was detected in either parent.@*CONCLUSION@#Non-invasive prenatal testing and CMA are both sensitive for the detection of chromosomal microdeletions and microduplications. CMA can help with clarification of genotype-phenotype correlation and facilitate prenatal diagnosis and genetic counseling for the family.

Genetic analysis of a fetus with partial 18p deletion / 中华医学遗传学杂志

OBJECTIVE@#To carry out prenatal diagnosis for a fetus with partial 18p deletion detected by non-invasive prenatal testing (NIPT).@*METHODS@#Peripheral blood and amniotic fluid samples of the pregnant woman and her husband were subjected to G-banded chromosomal karyotyping and more accurate chromosomal microarray analysis (CMA). The deletion sites were verified by fluorescence in situ hybridization (FISH) using centromeric probe Cep11 Aqua and telomeric probes Tel11q SO and Tel18 SG.@*RESULTS@#The karyotype of the fetus was determined as 46,XN,del(18)(p11.3). CMA has detected a 6.66 Mb deletion at 18p11.32-p11.31 (136 226-6 796 178). FISH confirmed the presence of a partial deletion at 18p. The mother was found to harbor the same deletion by chromosomal karyotyping as well as CMA analysis. No abnormality was found with the husband.@*CONCLUSION@#Although the fetus and its mother have both carried the same 18p deletion, no clinical manifestation was detected in the mother, which may be attributed to a low penetrance of the disorder. The fetus had died at 33 weeks of gestation with unknown cause.

Clinical and genetic analysis of a child with 2q37 deletion syndrome resulting from a translocation involving chromosome satellite / 中华医学遗传学杂志

OBJECTIVE@#To carry out cyto- and molecular genetic testing for a child featuring facial dysmorphism and attention deficit and hyperactive disorder.@*METHODS@#The child was subjected to routine peripheral blood lymphocyte chromosomal karyotyping, fluorescence in situ hybridization (FISH) and single nucleotide polymorphism array (SNP-array) analyses.@*RESULTS@#The child's facial dysmorphism included low-set ears, curly ear auricle, protuberance of eyebrow arch, nostril notch, short and flat philtrum and thin upper lip. SNP-array revealed that he has carried a 4.883 Mb deletion at 2q37. His chromosomal karyotype was ultimately determined as 45, XY, der(2;21) (2pter→ 2q37.3::21p13→ 21p10::20p10→ 20pter), der(20) (21qter→ 21q10::20q10→ 20qter).@*CONCLUSION@#A rare case of 2q37 deletion syndrome involving three chromosomes was discovered. Combined use of various cyto- and molecular genetic techniques is crucial for the diagnosis of chromosomal abnormalities with complex structures.

Analysis of a case with heterozygous 14q12 deletion and FOXG1 gene-related disease / 中华医学遗传学杂志

OBJECTIVE@#To describe the clinical and genetic characteristics of a child with 14q12q13.1 deletion involving the FOXG1 gene.@*METHODS@#Clinical manifestation of the child was analyzed. Peripheral blood sample of the patient was subjected to chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) analysis.@*RESULTS@#The male infant has developed feeding difficulty, poor sucking, lower limb tremor, and frontal bruising 8 days after birth. Magnetic resonance imaging revealed significant enlargement of bilateral ventricles and corpus callosum dysplasia. Chromosomal analysis revealed a karyotype of 46,XY,del(14)(q12q13.1), and SNP-array confirmed that there was a 9.6 Mb deletion in 14q11.2q13.1, which encompassed the FOXG1 gene.@*CONCLUSION@#For patients with brain development abnormalities, dyskinesia, cognitive impairment, speech disorder and other manifestations, copy number variation of the FOXG1 gene should be excluded. SNP-array should be carried out as early as possible to attain the diagnosis.

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.

Prenatal diagnosis of a fetus with 8q13.3 microdeletion through chromosomal microarray analysis / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of chromosomal microarray analysis (CMA) for the prenatal diagnosis of a fetus with structural anomaly detected by ultrasonography.@*METHODS@#The fetus and its parents were subjected to chromosomal karyotyping and CMA analysis.@*RESULTS@#The fetus was found to carry a 46,XN,t(8;11)(q21.2;q13) translocation which was inherited from its mother. CMA has found no copy number variations (CNVs) in both parents but a de novo 2.00 Mb microdeletion in the fetus at 8q13.3.@*CONCLUSION@#CMA is capable of detecting microdeletions and microduplications in fetuses with translocations detected by karyotyping analysis.

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.

Prenatal diagnosis and genetic analysis of two fetuses with paternally derived 17q12 microdeletions / 中华医学遗传学杂志

OBJECTIVE@#To reported on two fetuses diagnosed with 17q12 microdeletion syndrome.@*METHODS@#The two fetuses were respectively found to have renal abnormalities and polyhydramnios upon second and third trimester ultrasonography. Umbilical cord blood of the first fetus and amniotic fluid of the second fetus were subjected to single nucleotide polymorphism array (SNP-array) analysis. After 17q12 microdeletion was found in the first fetus, SNP-array was carried out on peripheral blood samples of the parents to determine its origin. With the medical history of the parents taken into consideration, the father underwent high-throughput sequencing for 565 urinary system-related genes to exclude pathogenic or likely pathogenic variants associated with congenital malformations of the urinary and reproductive systems.@*RESULTS@#In both fetuses, SNP-array has revealed a 1.42 Mb deletion at 17q12, or arr[hg19]17q12 (34 822 465-36 243 365) × 1. In both cases the microdeletion was inherited from the father, in whom no urinary disease-related pathogenic or likely pathogenic variants was identified.@*CONCLUSION@#Paternally derived 17q12 microdeletions probably underlay the genetic etiology of the two fetuses with renal ultrasound abnormalities and polyhydramnios. SNP-array can enable the diagnosis and facilitate genetic counseling and prenatal diagnosis for the families.

Prenatal diagnosis and genetic analysis of a fetus with Miller-Dieker syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a fetus with lissencephaly.@*METHODS@#Genomic DNA was extracted from amniotic fluid sample and subjected to copy number variation (CNV) analysis.@*RESULTS@#The fetus was found to harbor a heterozygous 5.2 Mb deletion at 17p13.3p13.2, which encompassed the whole critical region of Miller-Dieker syndrome (MDS) (chr17: 1-2 588 909).@*CONCLUSION@#The fetus was diagnosed with MDS. Deletion of the PAFAH1B1 gene may account for the lissencephaly found in the fetus.