Prenatal 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 fetus with bilateral lateral ventriculomegaly.@*METHODS@#Fetus umbilical cord blood and peripheral blood samples of its parents were collected. The fetus was subjected to chromosomal karyotyping, whilst the fetus and its parents were subjected to array comparative genomic hybridization (aCGH). The candidate copy number variation (CNV) were verified by qPCR, Application goldeneye DNA identification system was used to confirm the parental relationship.@*RESULTS@#The fetus was found to have a normal karyotype. aCGH analysis indicated that it has carried a 1.16 Mb deletion at 17p13.3, which partially overlapped with the critical region of Miller-Dieker syndrome (MDS), in addition with a 1.33 Mb deletion at 17p12 region, which is associated with hereditary stress-susceptible peripheral neuropathy (HNPP). Its mother was also found to harbor the 1.33 Mb deletion at 17p12. qPCR analysis confirmed that the expression levels of genes from the 17p13.3 and 17p12 regions were about the half of that in the normal control, as well as the maternal peripheral blood sample. Parental relationship was confirmed between the fetus and its parents. Following genetic counseling, the parents has chosen to continue with the pregnancy.@*CONCLUSION@#The fetus was diagnosed with Miller-Dieker syndrome due to the de novo deletion at 17p13.3. Ventriculomegaly may be an important indicator for prenatal ultrasonography in fetuses with MDS.

Analysis of ARX gene variant in a child with X-linked lissencephaly with abnormal genitalia / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic basis for a child with X-linked lissencephaly with abnormal genitalia (XLAG).@*METHODS@#A child with XLAG who had presented at the Third Affiliated Hospital of Zhengzhou University in May 2021 was selected as the study subject. Peripheral blood samples of the child and his parents were collected and subjected to high-throughput sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the result was analyzed by using bioinformatic software.@*RESULTS@#The child was found to have harbored a hemizygous c.945_948del variant in exon 2 of the ARX gene, which as a frameshifting variant has resulted in a truncated protein. His mother was found to be heterozygous for the variant, whilst his father was of wild type. The variant was unreported previously.@*CONCLUSION@#The hemizygous c.945_948del variant of the ARX gene probably underlay the XLAG in this patient. Above finding has provided a basis for the diagnosis and genetic counseling for this family.

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.

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

OBJECTIVE@#To carry out genetic diagnosis for a fetus.@*METHODS@#Chromosome G-banding and chromosomal microarray analysis (CMA) were carried out for a fetus with abnormal morphology of lateral cerebral fissure.@*RESULTS@#The karyotype of the fetus was normal, but CMA showed that it has carried a 1.4 Mb deletion at 17p13.3 region, which suggested a diagnosis of Miller-Dieker syndrome (MDS).@*CONCLUSION@#Familiarity with clinical features and proper selection of genetic testing method are crucial for the diagnosis of MDS. Attention should be paid to microdeletions and microduplications which can be missed by conventional chromosomal karyotyping.

Prenatal genetic analysis of two fetuses with Miller-Dieker syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform molecular cytogenetic study on two fetuses with abnormal ultrasound findings and analyze their genotype-phenotype correlation.</p><p><b>METHODS</b>G-banded karyotyping, single nucleotide polymorphism array (SNP array) and fluorescence in situ hybridization (FISH) were performed on amniotic fluid cells from both fetuses and peripheral blood samples from their parents. Results of SNP array were analyzed with bioinformatics software.</p><p><b>RESULTS</b>G-banded karyotyping failed to detect any abnormalities in both fetuses and their parents. SNP array detected a 2.484 Mb terminal deletion at 17p13.3 [arr[hg19] 17p13.3 (83 035-2 567 405)×1] in fetus 1 and a 3.295 Mb terminal deletion at 17p13.3p13.2 [arr[hg19] 17p13.3p13.2 (83 035- 3 377 560)×1] in fetus 2. Both deletions have overlapped with the critical region of Miller-Dieker syndrome (MDS) and involved candidate genes such as PAFAH1B1, YWHAE and CRK. In addition, SNP array and FISH analyses on the parental peripheral blood samples demonstrated that both 17p13.3 and 17p13.3p13.2 deletions were of de novo origin. Metaphase FISH performed on amniotic fluid cells confirmed the presence of 17p13.3 and 17p13.3p13.2 deletions detected by the SNP array, while metaphase FISH performed on the parents excluded any potential chromosome rearrangements.</p><p><b>CONCLUSION</b>Abnormal ultrasound features for fetuses with MDS mainly include central nervous system anomalies. SNP array can efficiently detect 17p13.3 microdeletions underlying MDS, and accurately map the breakpoints and involved genes, which may facilitate understanding of the genotype and phenotype correlations for MDS.</p>

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

<p><b>OBJECTIVE</b>To report on prenatal diagnosis of a fetus with Miller-Dieker syndrome (MDS) and explore its genotype - phenotype correlation.</p><p><b>METHODS</b>Chromosome karyotyping, bacterial artificial chromosome on beads (BACs-on-Beads, BoBs), fluorescence in situ hybridization (FISH), and single nucleotide polymorphism microarray (SNP array) were applied in conjunction for the prenatal diagnosis of a fetus with abnormal ultrasound findings.</p><p><b>RESULTS</b>A 17p13.3 microdeletion was detected with the BoBs assay, and the result was confirmed by FISH. With the SNP array, the deletion was mapped to chromosome 17, with its range determined to be 5.2 Mb. On high-resolution banding analysis and BoB assay, the deletion was not found in either parent.</p><p><b>CONCLUSION</b>The combined use of BoBs, FISH and SNP array has enabled prenatal diagnosis of a fetus with MDS. Attention should be paid to microdeletions and microduplications which can be missed by conventional chromosomal karyotyping analysis.</p>

Merosin-Deficient Congenital Muscular Dystrophy with Polymicrogyria and Subcortical Heterotopia: A Case Report

This paper reports the brain magnetic resonance imaging (MRI) findings of a case of merosin-deficient congenital muscular dystrophy (MDCMD) in a neonate and discusses the spectrum of brain involvement in MDCMD. A neonate presented hypotonia, increased serum creatine kinase levels, and polymicrogyria and subcortical heterotopia on brain MRI involving both posterior temporal and occipital lobes. Although these findings suggested Fukuyama muscular dystrophy, muscle biopsy showed dystrophic changes and an absence of merosin staining. We found that compound heterozygous mutation for c.2049_2050delAG (p.R683fs) and c.5866-2A>G in the LAMA2 gene which encodes Laminin-α2. To our knowledge, this is the second Korean case of MDCMD with polymicrogyria and subcortical heterotopias. This case shows that a range of brain structural malformations can be found in children with MDCMD and that the classification of congenital muscular dystrophy (CMD) is not complete yet, as indicated previously in reports suggesting other unclassified forms of CMD.

Routine Chromosomal Microarray Analysis is Necessary in Korean Patients With Unexplained Developmental Delay/Mental Retardation/Autism Spectrum Disorder

BACKGROUND: All over the world, chromosomal microarray (CMA) is now the first tier diagnostic assay for genetic testing to evaluate developmental delay (DD), mental retardation (MR), and autism spectrum disorder (ASD) with unknown etiology. The average diagnostic yield of the CMA test is known to be about 12.2%, while that of conventional G-banding karyotype is below 3%. This study aimed to assess the usefulness of CMA for the purpose of clinical diagnostic testing in the Korean population. METHODS: We performed CMA and multiplex ligation-dependent probe amplification (MLPA) tests in 96 patients with normal karyotype and unexplained DD, MR, or ASD. The CMA was conducted with CytoScan 750K array (Affymetrix, USA) with an average resolution of 100 kb. RESULTS: Pathogenic copy number variations (CNVs) were detected in 15 patients by CMA and in two patients by MLPA for four known microdeletion syndromes (Prader-Willi/Angelman syndrome, DiGeorge syndrome, Miller-Dieker syndrome and Williams syndrome) designated by National Health Insurance system in Korea. The diagnostic yield was 15.6% and 2.1%, respectively. Thirteen (13.5%) patients (excluding cases with pathogenic CNVs) had variants of uncertain clinical significance. There was one patient with a 17.1-megabase (Mb) region of homozygosity on chromosome 4q. CONCLUSIONS: Our findings suggest the necessity of CMA as a routine diagnostic test for unexplained DD, MR, and ASD in Korea.

Prenatal diagnosis of fetal gray matter heteropia in one case and literature review / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the prenatal ultrasonic manifestations of fetal gray matter heterotopias (FGMH) and evaluate the optimal method its prenatal diagnosis.</p><p><b>METHODS</b>The prenatal and postnatal ultrasound images and MRI images were analyzed for a fetus with a definitive diagnosis of FGMH. The detection rates of FGMH by prenatal ultrasound and MRI reported in literature were compared.</p><p><b>RESULTS</b>We identified 11 reports of FGMH from 1998 to 2015, involving 43 cases with prenatal diagnoses. Of the total of 44 cases (including our case), 32 that had been confirmed postpartum had prenatal ultrasound and MRI data, which showed a significantly lower detection rates of FGMH by prenatal ultrasound than by MRI (43.8% vs 93.8%, P<0.001).</p><p><b>CONCLUSION</b>Prenatal ultrasound can only detect subependymal heterotopia with characteristic manifestations, and the detection of other types of FGMH relies on MRI, which is currently the best option for prenatal diagnosis of FGMH.</p>

Analysis of DCX gene mutation in a patient featuring X-linked subcortical laminar heterotopia and epilepsy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect potential mutation of Doublecortin (DCX) gene in a patient featuring X-linked subcortical laminar heterotopia (X-SCLH) and epilepsy.</p><p><b>METHODS</b>Mutation of the DCX gene was screened by PCR and direct sequencing. Pathogenicity of the mutation was analyzed with a PolyPhen-2 software.</p><p><b>RESULTS</b>A de novo missense mutation c.971T>C (p.Phe324Ser) was discovered.</p><p><b>CONCLUSION</b>A diagnostic method for X-SCLH has been established, which may facilitate diagnosis and genetic counseling of patients featuring this disease.</p>

A Forensic Autopsy Case of Lissencephaly for Evaluating the Possibility of Child Abuse / 대한법의학회지

A 9-year-old Korean boy with lissencephaly was found dead at home. He had previously been diagnosed with lissencephaly that presented with infantile spasm on the basis of magnetic resonance imaging and electroencephalogram results. Antemortem chromosomal banding revealed a normal karyotype. A legal autopsy was requested to eliminate the possibility of neglect or abuse by his parents. The autopsy findings revealed type I lissencephaly with the associated microcephaly. No external wounds or decubitus ulcers were noted. Postmortem fluorescence in situ hybridization for the LIS1 locus and nucleotide sequence analysis of the whole coding regions of the LIS1 gene did not reveal any deletions. The antemortem and postmortem findings revealed that lissencephaly syndrome was associated with isolated lissencephaly sequence. External causes of death were excluded by the full autopsy and toxicology test results. Because patients with mental retardation are frequently victimized and suffer neglect or abuse, thorough external and internal examinations should be conducted at the time of autopsy.

Miller-Dieker Syndrome with der(17)t(12;17)(q24.33;p13.3)pat Presenting with a Potential Risk of Mis-identification as a de novo Submicroscopic Deletion of 17p13.3 / 대한진단검사의학회지

Miller-Dieker syndrome involves a severe type of lissencephaly, which is caused by defects in the lissencephaly gene (LIS1). We report the case of a female infant with der(17)t(12;17)(q24.33;p13.3)pat caused by an unbalanced segregation of the parental balanced translocation of 17p with other chromosomes. The proband presented with facial dysmorphism, arthrogryposis, and intrauterine growth retardation. Most cases of Miller-Dieker syndrome have a de novo deletion involving 17p13.3. When Miller-Dieker syndrome is caused by an unbalanced translocation, mild-to-severe phenotypes occur according to the extension of the involved partner chromosome. However, a pure partial monosomy derived from a paternal balanced translocation is relatively rare. In this case, the submicroscopic cryptic deletion in the proband was initially elucidated by FISH, and karyotype analysis did not reveal additional chromosome abnormalities such as translocation. However, a family history of recurrent pregnancy abnormalities strongly suggested familial translocation. Sequential G-banding and FISH analysis of the father's chromosomes showed that the segment of 17p13.3-->pter was attached to the 12qter. Thus, we report a case that showed resemblance to the findings in cases of a nearly pure 17p deletion, derived from t(12;17), and delineated by whole genome array comparative genomic hybridization (CGH). If such cases are incorrectly diagnosed as Miller-Dieker syndrome caused by de novo 17p13.3 deletion, the resultant improper genetic counseling may make it difficult to exactly predict the potential risk of recurrent lissencephaly for successive pregnancies.

Pattern of childhood neuronal migrational disorders in Oman

To record the pattern of different neuronal migrational disorders [NMD] and their associated neurological conditions. The data were collected at the Child Neurology Services of Sultan Qaboos University Hospital, Oman, from January 1993 to September 2006 from all children with psychomotor delay and epilepsy, who underwent brain imaging [mostly MRI]. The MR imaging was used for the diagnosis of a neuronal migration anomaly. There were 86 cases of NMD. Corpus callosum agenesis and lissencephaly/pachygyria formed the major group. There were 48 cases of corpus callosum agenesis, and 16 cases of lissencephaly/pachygyria. Other disorders were 10 cases of heterotopias, 5 schizencephaly, 3 holoprosencephaly, 2 polymicrogyria, and one each of hemimegalencephaly, and hydranencephaly. Developmental delay was the most common associated finding noted in 80 [93%] cases. Sixty-seven [77.9%] cases had motor deficit. Forty out of 86 [46.5%] cases had epilepsy. Partial/partial complex seizures were the most common at 13 out of 40 [32.5%]. Syndromic seizures were seen in 11 out of 40 [27.5%] cases. The seizures were controlled in only 3/40 [7.5%] cases. The NMD constitute a significant number of child neurology patients with psychomotor delay and intractable epilepsy. Exogenic and genetic factors affecting the early embryonic and fetal development from sixth to twenty-sixth weeks of gestation result in NMD. Recent genetic studies are defining the underlying mechanism and these studies will help in early diagnosis and possible prevention of NMD

Comparing Two Diagnostic Laboratory Tests for Several Microdeletions Causing Mental Retardation Syndromes: Multiplex Ligation-Dependent Amplification vs Fluorescent In Situ Hybridization / 대한진단검사의학회지

BACKGROUND: Microdeletion syndromes not detectable by conventional cytogenetic analysis have been reported to occur in approximately 5% of patients with unexplained mental retardation (MR). Therefore, it is essential to ensure that patients with MR are screened for these microdeletion syndromes. Mental retardation syndrome multiplex ligation-dependent probe amplification (MRS-MLPA) is a new technique for measuring sequence dosages that allows for the detection of copy number changes of several microdeletion syndromes (1p36 deletion syndrome, Williams syndrome, Smith-Magenis syndrome, Miller-Dieker syndrome, DiGeorge syndrome, Prader-Willi/Angelman syndrome, Alagille syndrome, Saethre-Chotzen syndrome, and Sotos syndrome) to be processed simultaneously, thus significantly reducing the amount of laboratory work. METHODS: We assessed the performance of MLPA (MRC-Holland, The Netherlands) for the detection of microdeletion syndromes by comparing the results with those generated using FISH assays. MLPA analysis was carried out on 12 patients with microdeletion confirmed by FISH (three DiGeorge syndrome, four Williams syndrome, four Prader-Willi syndrome, and one Miller-Dieker syndrome). RESULTS: The results of MLPA analysis showed a complete concordance with FISH in 12 patients with microdeletion syndromes. CONCLUSIONS: On the basis of these results, we conclude that MLPA is an accurate, reliable, and cost-effective alternative to FISH in the screening for microdeletion syndromes.

Neuronal migration disorder; a case report of subcortical band heterotopia associated with corpus callosum agenesis

Subcortical band heterotopia [SBH] or 'double cortex' is a congenital brain abnormality that results from aberrant migration of neurons during development of the cortex. MRI shows a continuous band of heterotopic gray matter located between the cortex and ventricular walls, separated from them by a thin layer of white matter. The condition is quite rare, found predominantly in females, and is occasionally familial with an X-linked dominant inheritance. Corpus callosum agenesis is another brain abnormality, more common than SBH, diagnosed during neurological examinations for developmental delay. We report a 6-month-old boy with SBH and corpus callosum agenesis associated with uncommon clinical and radiological findings such as polymicrogyria and periventricular cystic area

A Case of Miller-Dieker Syndrome with Infantile Spasm and Lennox-Gastaut Syndrome / 대한소아신경학회지

Miller-Dieker syndrome is a contiguous gene deletion syndrome involving chromosome 17p13.3, which is characterized by type 1(classical) lissencephaly and typical craniofacial abnormalities. Children with Miller-Dieker syndrome have profound psychomotor retardation, seizures that often are intractable, chronic feeding problems that lead to recurrent pneumonia, and shortened lifespan. We have experienced a Miller-Dieker syndrome female who has lived to 8years, showing severe mental and motor retardation and intractable epilepsy. She was diagnosed as Miller-Dieker syndrome in the neonatal period, showing typical facial features, type 1 lissencephaly, and chromosome 17p13.3 microdeletion in fluorescence in situ hybridization. Infantile spasm occurred at 4 months of age and progressed to Lennox-Gastaut syndrome at 3 years and 6 months, both of which were not controlled by antiepileptic drugs.

Síndrome de Meckel-Gruber: relato de caso / Meckel-Gruber syndrome: a case report

Os autores relatam um caso de diagnóstico pré-natal de síndrome de Meckel-Gruber em gestante de 12 anos de idade. A primeira ultra-sonografia, realizada na 32ª semana, identificou feto único portador de microcefalia, volumosa encefalocele na linha média da região occipital, lábio leporino completo bilateral e fenda palatina. Os rins encontravam-se de dimensões e ecotextura aumentadas, medindo cerca de 12 cm de comprimento, levando a importante aumento do volume abdominal. A genitália fetal não foi identificada, sendo visualizada pequena imagem cística na sua topografia.Em função da presença de oligodramnia, foi realizada ressonância magnética na 33ª semana, que confirmou os achados ultra-sonográficos e demonstrou uma lisencefalia. Na 34ª semana, a gestação evoluiu com amniorrexe prematura, sendo realizada cesariana, com retirada de natimorto, posteriormente encaminhado à necropsia. Polidactilia foi a única alteração presente não-identificada pelos métodos de imagem.

The authors report a case of antenatal ultrasound diagnosis of Meckel-Gruber syndrome in a 12-year-old pregnant girl. The first scan done at 32 weeks of gestation revealed a single fetus withmicrocephaly, large encephalocele in the occipital mid-line region, bilateral complete cleft lip, and cleft palate. The kidneys and their ecotexture were found to be enlarged, measuring about 12 cm in length, causing an important enlargement of the abdomen. The fetus' genitals were not identified, but a small cystic image was visualized in their topography. Due to the presence of oligohydramnios, a magnetic resonance was performed at 33 weeks of gestation,which confirmed the sonographic findings and demonstrated a lisencephaly. A premature rupture of membranes occurred at 34 weeks of gestation, upon which a caeserian section was performed, the stillborn baby removed and subsequently taken for a necropsy. Polydactyly was the only anomaly present which was not identified by the imaging methods used.

Epilepsia e desordens de malformação do desenvolvimento cortical / Epilepsy and malformations of cortical development disorders

OBJETIVOS: As desordens do desenvolvimento cortical (DDC) constituem a segunda causa de epilepsia refratária. Diversas patologias estão incluídas nas DDC. Seu diagnóstico foi facilitado com o desenvolvimento na neuroimagem. MÉTODOS: No presente artigo, apresentamos sete casos divididos em três grupos, de acordo com o mecanismo de produção das DDC: 1) anormalidades da proliferação e diferenciação de neurônios da glia; 2) anormalidades de migração neuronal; 3) anormalidades na organização neuronal. A investigação consistiu em história mais exame neurológico, avaliação neuropsicológica, ressonância magnética e eletrencefalograma. RESULTADOS E CONCLUSÕES: Três pacientes apresentaram displasia cortical focal, dois apresentaram heterotopia em banda, um paciente apresentava lisencefalia e uma apresentava esquizencefalia. Todos os pacientes apresentavam epilepsia de difícil controle. Malformações corticais constituem um grupo heterogêneo de causas de epilepsia de difícil controle. É importante para o manejo médico que as diversas formas de malformações corticais sejam conhecidas e diagnosticadas, o que foi facilitado pelo advento da ressonância magnética.

OBJECTIVES: Cortical development disorders (CDD) are the second cause of refratary epilepsy. Various patologies are included in the CDD. The diagnosis was easy with the continuous development of the neuroimaging. METHODS: In the present paper we show seven cases divided in three groups, accourding with the mecanism of production of the CDD: 1) proliferation and diferentiation abnormalities of the glial cells; 2) abnormalities of the neuronal migration; 3) abnormalities of the neuronal organization. The investigation consisted in story and neurological examination, neuropsicological avaliation, magnetic ressonance imaging and eletroencephalogram. RESULTS AND CONCLUSION: Three patients had focal cortical dysplasia; two had heterotopic band, one patient had lissecephaly and another had schizencephaly. All the patients had refractory epilepsy. Cortical malformations are a heterogeneous group of refractory epilepsy. Knowing and diagnosing these different types of cortical malformations are important steps for their treatment, and were facilitated by de advent of magnetic resonance imaging.

A Case Report of Miller-Dieker Syndrome / 대한주산의학회잡지

Miller-Dieker Syndrome (MDS) is a contiguous gene deletion syndrome of chromosome 17p13.3, characterized by classical lissencephaly (lissencephaly type 1) and distinct facial features. Children with MDS present with severe developmental delay, epilepsy and feeding problems. The lissencephaly represents the severe end of the spectrum with generalized agyria, or agyria and some frontal pachy- gyria. Prenatal diagnosis is available and consists of fetal chromosomal analysis by karyotyping or fluorescence in situ hybridization (FISH), on chorion villus sampling or amniocentesis. Sonographic diagnosis in general cannot be accomplished earlier than late second trimester, when the characteristic cerebral anomalies can be noted. The progressive microcephaly and failure of development of both sulci and gyri are suggestive of lissencephaly. We report the case of a pregnant woman of 24 weeks gestation who presented with ventriculomegaly on antenatal sonography and hydrocephalus, and corpus callosum agenesis on fetal MRI, which was diagnosed as MDS by karyotyping and FISH on amniocentesis.