Clinical and genetic analyses of Joubert syndrome in children / 中国当代儿科杂志

OBJECTIVES@#To study the clinical and genetic features of Joubert syndrome (JS) in children.@*METHODS@#A retrospective analysis was performed on the clinical data, genetic data, and follow-up data of 20 children who were diagnosed with JS in the Department of Children's Rehabilitation, the Third Affiliated Hospital of Zhengzhou University, from January 2017 to July 2022.@*RESULTS@#Among the 20 children with JS, there were 11 boys and 9 girls. The common clinical manifestations were developmental delay (20 children, 100%), abnormal eye movement (19 children, 95%), and hypotonia (16 children, 80%), followed by abnormal respiratory rhythm in 5 children (25%) and unusual facies (including prominent forehead, low-set ears, and triangular mouth) in 3 children (15%), and no limb deformity was observed. All 20 children (100%) had the typical "molar tooth sign" and "midline cleft syndrome" on head images, and 6 children (30%) had abnormal eye examination results. Genetic testing was performed on 7 children and revealed 6 pathogenic genes, i.e., the CPLANE1, RPGRIP1L, MKS1, CC2D2A, CEP120, and AHI1 genes.@*CONCLUSIONS@#For children with developmental delay, especially those with abnormal eye movement and hypotonia, it is recommended to perform a head imaging examination to determine the presence or absence of "molar tooth sign" and "midline cleft syndrome", so as to screen for JS to avoid missed diagnosis and misdiagnosis. There are many pathogenic genes for JS, and whole-exome sequencing can assist in the diagnosis of JS.

Analysis of genetic variants and clinical manifestations of two children with Kabuki syndrome / 中华医学遗传学杂志

OBJECTIVE@#To report on two children with Kabuki syndrome due to variants of the KMT2D gene and summarize their clinical and genetic characteristics.@*METHODS@#Two children who had presented at the Ningbo Women and Children's Hospital respectively on August 19 and November 10, 2021 were selected as the study subjects. Clinical data were collected. Both children were subjected to whole exome sequencing (WES), and candidate variants were validated by Sanger sequencing.@*RESULTS@#Both children had featured motor and language developmental delay, facial dysmorphism and mental retardation. Genetic testing revealed that both had harbored de novo heterozygous variants of the KMT2D gene, namely c.10205del (p.Leu3402Argfs*3) and c.5104C>T (p.Arg1702*), both of which were rated as pathogenic variants based on the guidelines from the American College of Medical Genetics and Genomics (ACMG).@*CONCLUSION@#The c.10205del (p.Leu3402Argfs*3) and c.5104C>T (p.Arg1702*) variants of the KMT2D gene probably underlay the pathogenesis in these two children. Above finding has not only provided a basis for their diagnosis and genetic counseling, but also enriched the spectrum of KMT2D gene variants.

Analysis of a case of Multiple pterygium syndrome due to a novel variant of CHRNG gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic etiology of a child with multiple pterygium syndrome (MPS).@*METHODS@#A child with MPS who was treated at the Orthopedics Department of Guangzhou Women and Children's Medical Center Affiliated to Guangzhou Medical University on August 19, 2020 was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples of the child and her parents were also collected. Whole exome sequencing (WES) was carried out for the child. Candidate variant was validated by Sanger sequencing of her parents and bioinformatic analysis.@*RESULTS@#The child, an 11-year-old female, had a complain of "scoliosis found 8 years before and aggravated with unequal shoulder height for 1 year". WES results revealed that she has carried a homozygous c.55+1G>C splice variant of the CHRNG gene, for which both of her parents were heterozygous carriers. By bioinformatic analysis, the c.55+1G>C variant has not been recorded by the CNKI, Wanfang data knowledge service platform and HGMG databases. Analysis with Multain online software suggested that the amino acid encoded by this site is highly conserved among various species. As predicted with the CRYP-SKIP online software, the probability of activation and skipping of the potential splice site in exon 1 caused by this variant is 0.30 and 0.70, respectively. The child was diagnosed with MPS.@*CONCLUSION@#The CHRNG gene c.55+1G>C variant probably underlay the MPS in this patient.

Clinical characteristics and genetic analysis of a fetus with Melnick-Needles syndrome due to variant of FLNA gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of a fetus with Melnick-Needles syndrome (MNS).@*METHODS@#A fetus with MNS diagnosed at Ningbo Women and Children's Hospital in November 2020 was selected as the study subject. Clinical data was collected. Pathogenic variant was screened by using trio-whole exome sequencing (trio-WES). Candidate variant was verified by Sanger sequencing.@*RESULTS@#Prenatal ultrasonography of the fetus had shown multiple anomalies including intrauterine growth retardation, bilateral femur curvature, omphalocele, single umbilical artery, and oligohydramnios. Trio-WES revealed that the fetus has harbored hemizygous c.3562G>A (p.A1188T) missense variant of the FLNA gene. Sanger sequencing confirmed that the variant was maternally derived, whilst its father was of a wild type. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be likely pathogenic (PS4+PM2_Supporting+PP3+PP4).@*CONCLUSION@#The hemizygous c.3562G>A (p.A1188T) variant of the FLNA gene probably underlay the structural abnormalities in this fetus. Genetic testing can facilitate accurate diagnosis of MNS and provide a basis for genetic counseling for this family.

Clinical phenotype and genetic analysis of a child with 3p26.3p25.3 deletion / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with facial dysmorphism and multiple malformations.@*METHODS@#The child, born at 34+6 weeks' gestation due to premature rupture of amniotic membrane, dichorionic diamniotic twinning and gestational diabetes, was subjected to chromosomal karyotyping analysis and copy number variations sequencing (CNV-seq).@*RESULTS@#The child was found to have facial dysmorphism, hypospadia, cryptorchidism and hypotonia. He was found to have a 46,XY,del(3)(p26) karyotype in addition with a 9.80 Mb deletion (chr3: 60 000-9 860 000) encompassing 33 protein coding genes.@*CONCLUSION@#The 3p26.3p25.3 deletion probably underlay the multiple malformations in this child. Continuous follow-up is required to improve his quality of life.

Analysis of clinical features and genetic variant in a neonate with Au-Kline syndrome due to a de novo variant of the HNRNPK gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical phenotype and genetic basis of a neonate with Au-Kline syndrome (AKS).@*METHODS@#Clinical data and result of genetic testing of a neonate with AKS who was admitted to the Affiliated Provincial Children's Hospital of Anhui Medical University in January 2021 were retrospectively analyzed. Relevant literature was searched from the Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure and PubMed databases using key words "Au Kline syndrome", "Au-Kline syndrome", "HNRNPK" and "AKS". The research period was set as from January 1, 2000 to December 31, 2020.@*RESULTS@#The male newborn has manifested feeding difficulties, hypotonia, absence of the upper jaw to the uvula and facial dysmorphism. Trio-whole exome sequencing revealed that he has harbored a frameshift c.478dupA (p.Ile160AsnfsTer7) variant of the HNRNPK gene, which was varified by Sanger sequencing to have a de novo origin. The variant has not been included in the databases. Based on the guidelines from the American College of Medical Genetics and Genomics, the variant was rated as pathogenic (PVS1+PS2+PM2_Supporting). Literature retrieval has identified 14 children with AKS and de novo mutations of the HNRNPK gene. Their clinical manifestations have included growth and motor retardation, various degree of mental retardation, facial dysmorphism and a high frequency of congenital heart malformations.@*CONCLUSION@#The AKS in this child may be attributed to the c478dupA frameshifting variant of the HNRNPK gene. Diagnosis of AKS should be suspected for children with mental retardation and multiple congenital malformation syndromes including Kabuki syndrome.

Clinical features and genetic analysis of a case of Wiedemann-Steiner syndrome due to variant of KMT2A gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and genetic etiology of a child with Wiedemann-Steiner syndrome.@*METHODS@#A child with WSS who was admitted to the Hematology Department of Tianjin Children's Hospital in May 2021 was selected as the subject. Clinical data of the child was collected. Peripheral blood samples were collected from the child and his parents for the extraction of genomic DNA. The child was subjected to whole exome sequencing, and candidate variant was verified by Sanger sequencing of the child and his parents.@*RESULTS@#The main clinical features of the child have included pancytopenia, growth and mental retardation, and facial dysmorphism. Whole exome sequencing revealed that the child has harbored a heterozygous variant of the KMT2A gene, namely c.7804delA (p.M2602Cfs*39). Sanger sequencing verified the variant to be de novo in origin. The variant was unreported previously and predicted to be pathogenic based on the guidelines of American College of Medical Genetics and Genomics (PVS1+PS2+PM2).@*CONCLUSION@#The heterozygous c.7804delA (p.M2602Cfs*39) variant of the KMT2A gene probably underlay the WSS in this child. Above finding has enriched the mutational spectrum and clinical phenotypes of the KMT2A gene.

Clinical and genetic analysis of three children with KBG syndrome due to novel variants of ANKRD11 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of three children with KBG syndrome.@*METHODS@#Clinical data of the three children from two families who have presented at the First Affiliated Hospital of Zhengzhou University between October 2019 and September 2020 and their family members were collected. Trio-whole exome sequencing (trio-WES) and Sanger sequencing were carried out.@*RESULTS@#All children had feeding difficulties, congenital heart defects and facial dysmorphism. The sib- pair from family 1 was found to harbor a novel de novo heterozygous c.6270delT (p.Q2091Rfs*84) variant of the ANKRD11 gene, whilst the child from family 2 was found to harbor a novel heterozygous c.6858delC (p.D2286Efs*51) variant of the ANKRD11 gene, which was inherited from his mother who had a mild clinical phenotype.@*CONCLUSION@#The heterozygous frameshift variants of the ANKRD11 gene probably underlay the disease in the three children. Above findings have enriched the spectrum of the ANKRD11 gene variants.

Analysis of three patients with KBG syndrome and epileptic seizures due to variants of ANKRD11 gene / 中华医学遗传学杂志

OBJECTIVE@#To summarize the clinical phenotype and genotypic characteristics of 3 patients with KBG syndrome and epileptic seizure.@*METHODS@#Clinical data of the patients were collected. Family-trio whole exon sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing.@*RESULTS@#Patients 1 and 2 were boys, and patient 3 was an adult woman. All patients had epileptic seizures and mental deficiency. Their facial features included triangular face, low hair line, hypertelorism, large forward leaning auricles, broad nasal bridge, upturned nostrils, long philtrum, arched upper lip, and macrodontia. The two boys also had bilateral Simian creases. WES revealed that the three patients all harbored heterozygous de novo frameshift variants in exon 9 of the ANKRD11 gene including c.2948delG (p.Ser983Metfs*335), c.5397_c.5398insC (p.Glu1800Argfs*150) and c.1180_c.1184delAATAA (p.Asn394Hisfs*42). So far 291 patients with ANKRD11 gene variants or 16q24.3 microdeletions were reported, with over 75% being de novo mutations.@*CONCLUSION@#Above findings have enriched the spectrum of ANKRD11 gene mutations underlying KBG syndrome. WES is helpful for the early diagnosis of KBG, and provided reference for genetic counseling of this disease.

Analysis of ADNP gene variant in a child with Helsmoortel-van der Aa syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child manifesting with intellectual disability, language delay and autism spectrum disorder.@*METHODS@#Genomic DNA was extracted from peripheral blood samples of the child and his family members, and subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing and interpreted according to the guidelines of the American College of Medical Genetics and Genomics.@*RESULTS@#The child was found to harbor a heterozygous c.568C>T (p.Q190X) nonsense variant of the ADNP gene, which was not detected in either parent by Sanger sequencing.@*CONCLUSION@#The clinical and genetic testing both suggested that the child has Helsmoortel-van der Aa syndrome due to ADNP gene mutation, which is extremely rare in China.

Analysis of a case with Xia-Gibbs syndrome due to variant of AHDC1 gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical and genetic characteristics of a child featuring Xia-Gibbs syndrome.@*METHODS@#Whole exome sequencing was carried out for the child.@*RESULTS@#The patient has presented with developmental delay, hypotonia, strabismus and snoring. Cranial MRI revealed hypomyelination, while the EEGs were normal. Genetic testing revealed a de novo variant of the AHDC1 gene, namely c.730delA (p.Ile244Serfs*16), which was classified as pathogenic (PVS1+PS2+PM2). Together with 60 cases from the literature, individuals harboring a AHDC1 variant commonly have delayed motor milestones, speech delay, facial dysmorphism and hypotonia. Dysgenesis of corpus callosum is also common. In total 47 AHDC1 variants have been reported, among which truncating variants were the most common type.@*CONCLUSION@#The c.730delA (p.Ile244Serfs*16) variant of the AHDC1 gene probably underlay the Xia-Gibbs syndrome in this patient. Above finding has provided a basis for the clinical diagnosis.

Phenotype and genotype analysis of a pedigree affected with Joubert syndrome due to variant of TMEM237 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the pathogenesis of two siblings (including a fetus) from a pedigree affected with Joubert syndrome.@*METHODS@#Peripheral blood samples of the proband and his parents as well as amniotic fluid and abortion tissues of the fetus were collected. Part of the samples were used for the extraction of DNA, and whole exome sequencing (WES) was carried out to screen potential variants in the proband and his parents. Suspected variants were subjected to bioinformatics analysis with consideration of the clinical phenotype, and were verified by Sanger sequencing of the proband, fetus and their parents.The remainders were used for the extraction of RNA, and the mechanism of splicing variant was validated by reverse transcription-PCR (RT-PCR).@*RESULTS@#WES showed that both patients have carried c.175C>T (p.R59X) and c.553+1G>A compound heterozygous variants of the TMEM237 gene. Among these, c.175C>T was a nonsense mutation inherited from the asymptomatic mother, while c.553+1G>A was an alternative splicing mutation inherited from the asymptomatic father. RT-PCR showed that this variant has resulted in aberrant splicing by exon skipping.@*CONCLUSION@#The compound heterozygous variants of the TMEM237 gene probably underlay the etiology of Joubert syndrome in this pedigree. Above finding has enriched the phenotype and variant spectrum of the TMEM237 gene, and facilitated genetic counseling and prenatal diagnosis for the family.

Phenotypic analysis and variant identification of a fetus with Joubert syndrome 17 / 中华医学遗传学杂志

OBJECTIVE@#To analyze the phenotype and genetic variant of a fetus with dysplasia of cerebellar vermis.@*METHODS@#Gestational status and family history of the gravida was taken in combination with the imaging results of the fetus. Following elected abortion, fetal tissue and peripheral blood samples of the couple were collected for the extraction of genome DNA. Whole exome sequencing was carried out to screen potential variant associated with the phenotype of the proband. Specific PCR primers were designed to verify the results by Sanger sequencing.@*RESULTS@#Prenatal ultrasound revealed that the fetal vermis cerebellum was poorly developed, which was similar to the previous pregnancy. Whole exome sequencing revealed that the fetus has carried compound heterozygous variants of the CPLANE1 gene, namely c.7978C>T and c.7169delT, which were respectively inherited from the husband and wife.@*CONCLUSION@#The c.7978C>T and c.7169delT compound heterozygous variants of the CPLANE1 gene probably underlay the dysplasia of cerebellar vermis in the fetus, which has provided a basis for genetic counseling and prenatal diagnosis.

Wiedemann-Steiner syndrome due to novel nonsense variant of KMT2A gene in a case / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with unexplained global developmental delay (GDD), seizure, and facial deformity.@*METHODS@#Whole exome sequencing (WES) was carried out for the patient. Candidate variants were verified by Sanger sequencing of the patient and his parents.@*RESULTS@#WES revealed that the patient has carried a previously unreported de novo heterozygous nonsense c.4906C>T (p.Arg1636Ter) variant of the KMT2A gene, Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.4906C>T variant of KMT2A gene was predicted to be pathogenic (PVS1+ PS2+ PM2+PP3).@*CONCLUSION@#The heterozygous nonsense c.4906C>T (p.Arg1636Ter) variant of the KMT2A gene probably underlay the disease in the child. Above finding has enriched the spectrum of pathogenic variants of the KMT2A gene.

Analysis of a case of Warburg micro syndrome type 1 due to variant of RAB3GAP1 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of a child featuring developmental delay.@*METHODS@#The child was subjected to whole exome sequencing. Candidate variant was verified by Sanger sequencing.@*RESULTS@#Whole genome sequencing revealed that the child has carried compound heterozygous variants c.2607-1G>C and c.899 + 2dupT of the RAB3GAP1 gene, which were respectively derived from her mother and father.@*CONCLUSION@#A rare case of Warburg micro syndrome type 1 was diagnosed. The phenotype of the child was consistent with the literature, in addition with dysplasia of palatine arch, prominent high palatal arch and tooth dysplasia. Above finding has provided a basis for genetic counseling and prenatal diagnosis for the family.

CHILD syndrome: successful treatment of skin lesions with topical lovastatin and cholesterol lotion

Abstract: CHILD syndrome (Congenital Hemidysplasia, Ichthyosiform erythroderma, Limb Defects) is a rare X-linked dominant disease. The authors report a 2-month-old patient presenting with typical features of CHILD syndrome that was treated with a topical solution containing cholesterol and lovastatin, with complete clearance of her CHILD nevus. The changes in skin lipid metabolism that explain the CHILD ichthyosiform nevus and their correction through topical application of cholesterol and lovastatin are discussed.

Wiedemann-Steiner syndrome with a novel pathogenic variant in KMT2A: a case report / Síndrome de Wiedemann-Steiner por una nueva variante patogénica en KMT2A: reporte de un caso

Abstract Case Description: We report the case of a one-year-old girl who was diagnosed with Wiedemann-Steiner Syndrome based on the identification of a novel de novo frameshift mutation in the KMT2A gene by whole exome sequencing and supported by her clinical features. Clinical Findings: KMT2A mutations cause Wiedemann-Steiner Syndrome, a very rare genetic disorder characterized by congenital hypertrichosis, short stature, intellectual disability, and distinct facial features. Treatment and Outcome: Whole exome sequencing identified a novel frameshift variant: c. 4177dupA (p.Ile1393Asnfs * 14) in KMT2A; this change generates an alteration of the specific binding to non-methylated CpG motifs of the DNA to the protein. The genotype and phenotype of the patient were compared with those of earlier reported patients in the literature. Clinical Relevance: In diseases with low frequency, it is necessary to establish a genotype-phenotype correlation that allows the establishment of therapeutic and follow-up goals. The phenotype comparation with other reported cases did not show differences attributable to sex or age among patients with Wiedemann-Steiner Syndrome. Whole exome sequencing allows identifying causality in conditions with high clinical and genetic heterogeneity like hypertrichosis.

Resumen Descripción del caso: Se reporta el caso de una paciente femenina de un año de edad, diagnosticada con Síndrome de Wiedemann-Steiner basado en la identificación de una nueva variante patogénica de novo de tipo frameshift en el gen KMT2A Mediante secuenciación de exoma usando el enfoque de trio, sumado a sus características clínicas. Hallazgos clínicos: las mutaciones en KMT2A causan el Síndrome de Wiedemann-Steiner, un desorden genético muy raro caracterizado por hipertricosis congénita, talla baja, retardo mental variable y fenotipo facial distintivo, los cuales se encuentran en la paciente reportada. Resultado: La Secuenciación de exoma completo encontró una variante de tipo frameshift: c.4177dupA (p. Ile1393Asnfs * 14) en KMT2A, este cambio a nivel génico genera una alteración de la unión específica a motivos CpG no metilados del DNA a la proteína. El genotipo y el fenotipo de la paciente fue comparado con los pacientes reportados previamente en la literatura. Relevancia clínica: En enfermedades con baja frecuencia como la aquí reportada es necesario establecer correlaciones genotipo-fenotipo que permitan establecer planes terapéuticos y de seguimiento. El análisis realizado no evidenció diferencias atribuibles a sexo o edad entre los pacientes diagnosticados con Síndrome de Weidemann-Steiner. La secuenciación de exoma permitió identificar causalidad en este caso, cuya característica principal de hipertricosis se asocia con alta heterogeneidad clínica y genética.

Vohwinkel syndrome: ichthyosiform variant in a family

Abstract: Vohwinkel syndrome belongs to the group of hereditary palmoplantar keratoderma, having an autosomal dominant inheritance. In this report, the authors present a case of a four-year-old boy with diffuse scaling over his entire body and transgredient palmoplantar hyperkeratosis with some fissured areas. Family evaluation revealed that his mother and other family members were affected. Based on his clinical findings and on family history, the diagnosis of the ichthyotic Vohwinkel syndrome subtype, characterized by generalized ichthyosis and palmoplantar hyperkeratosis, was established.

Olmsted Syndrome Caused by a Heterozygous p.Gly568Val Missense Mutation in TRPV3 Gene

Olmsted syndrome (OS) is a rare congenital skin disorder characterized by severe palmoplantar and periorificial keratoderma, alopecia, onychodystrophy, and severe pruritus. Recently, pathogenic ‘gain-of-function‘ mutations of the transient receptor potential vanilloid 3 gene (TRPV3), which encodes a cation channel involved in keratinocyte differentiation and proliferation, hair growth, inflammation, pain and pruritus, have been identified to cause OS. Due to the rarity, the pattern of inheritance of OS is still unclear. We report a case of OS in a 3-year-old Korean girl and its underlying gene mutation. The patient presented with a disabling, bilateral palmoplantar keratoderma with onychodystrophy. She also exhibited pruritic eczematous skin lesions around her eyes, ears and gluteal fold. Genetic analysis identified a heterozygous p.Gly568Val missense mutation in the exon 13 of TRPV3. To our knowledge, this is the first case of OS in the Korean population showing a missense mutation p.Gly573Ser.