Objective To explore the clinical and genetic features in the pedigree of Cb1X type X-linked methylmalonic aciduria. Methods Clinical data of one child with X-linked methylmalonic aciduria diagnosed by blood and urine analysis were analyzed retrospectively. Targeted next-generation sequencing has been performed to detect the mutation of methylmalonic aciduria-related genes. Results The boy started presenting with seizures and severe mental retardation at 2 months of age. At 5 months of age, he had the manifestations of seizures, severe mental retardation, increased methylmalonic acid in urinary, increased propionylcarnitine in blood and increased plasma homocysteine, and met the requirements for the diagnosis of methylmalonic aciduria complicated with hyperhomocysteinemia. No mutation was detected in his MMA-related autosomal genes. However, a hemizygote mutation c.344C?>?T (p.Ala115Val) was identiifed in exon 3 of HCFC1 in X chromosome, which conifrmed the CblX type methylmalonic aciduria. His parents were healthy. His elder brother also manifested severe psychomotor retardation with intractable epilepsy, and died at 6 months of age with unknown cause. His mother carried the same mutation and had slightly elevated urine methylmalonic acid and plasma total homocysteine. His father did not carry the mutation. Conclusion A pedigree of a rare Cb1X type X-linked methylmalonic acidemia is ifrstly diagnosed in China by the new generation sequencing technology.

Objective To investigate the clinical features,karyotype,and the prenatal diagnosis for his sibling of a Chinese patient with rare ring chromosome 20 syndrome induced intractable epilepsy.Methods The clinical data of the patient diagnosed in Peking University People's Hospital were collected.The clinical manifestations,chromosome karyotype were summarized.Results The proband,a boy,started to show intermittent tonic seizures or atypical absence seizures and psychomotor retardation from the age of 11 months.Several anti-epilepsy drugs and globulin had been tried without effect.Common karyotype analysis and epilepsy-related genes analysis revealed no abnormality.However,abnormal karyotype 46,XY,r(20)(p13q13.3) in his peripheral blood lymphocytes was found by high resolution chromosome karyotype analysis with 550 G-banding,and the diagnosis of ring chromosome 20 syndrome,type Ⅱ was confirmed.The mother of the patient underwent amniocentesis at the midterm of the second pregnancy.The cultured amniocytes karyotypes were normal.The second child(a boy) of the family was 1 year old without epilepsy and the psychomotor development was normal.Conclusions Ring chromosome 20 syndrome is a rare human chromosome abnormality.The syndrome is associated with epileptic seizures,behavior disorders and mental retardation.Since karyotype testing is not a routine investigation for the patient with epilepsy,the diagnosis of ring chromosome 20 syndrome is usually delayed or misdiagnosed.The karyotype analysis should be considered for the etiological study of the patients with intractable epilepsy with unknown origin.

Objective To explore the diagnosis of cystinosis.Methods The clinical and biochemical information, and gene detection results in a child with cystinosis was retrospective analyzed.Results Four-year-old female presented with photophobia and corneal crystal was found by ophthalmic examination at 2 years old, bilateral kidney stone was found, accompanied by development delay and rickets at 3 years old. Gas chromatography analysis in urine showed that a variety of amino acids were increased, and urine sugar and urinary micro-protein were also increased, which were in accordance with fanconi syndrome. The blood free carnitine was decreased, ester acyl carnitine spectrum was normal, and multi-amino acids such as lysine, valine and arginine were decreased. Gene analysis showed a homozygous mutation of c.696C>G (p.323 N>K) inCTNS gene, which was a known mutation. Both her parents were carrier of heterozygous mutation of c.696C>G inCTNS gene.Conclusion Child with kidney stone, renal damage, combined by multi-system damage such as eyes, bone, and thyroid should be paid attention to identify the cystinosis.

Objective:To summarize and compare the characteristics of oral microbiota in women during the preconception period and the third trimester.Methods:This retrospective cohort study involved 55 women who were recruited in the Preconceptional Offspring Trajectory Study (PLOTS) conducted by Fudan University and followed up to the third trimester in the Maternal and Child Health Care Hospital of Jiading District of Shanghai from September 2016 to December 2019. A total of 110 unstimulated saliva samples were collected in the preconception period ( n=55) and the third trimester ( n=55). Features of oral microbiota in the samples were analyzed by 16S rRNA gene-based sequencing. Moreover, the related factors were also analyzed. Paired t test or Wilcoxon matched-pairs signed-ranks test were used to analyze the differences in α-diversity during preconception and the third trimester; t test, analysis of variance (ANOVA), Kruskal-Wallis test and Mann-Whitney U test for comparison between groups with different characteristics and permutational multivariate analysis of variance (PerMANOVA) for β-diversity were used; Linear discriminant analysis (LDA) effect size (LEfSe 1.0) was used to identify the iconic oral flora. Results:(1) The Ace index of oral microbiota was significantly lower in the third trimester than that in the preconception period [661.14(578.15-752.85) vs 730.64 (632.40-911.00), T=1 077.00, P=0.010]. There was also a significance difference in β-diversity ( F=12.539, R2=0.104, P=0.001). Some species such as Saccharibacteria_TM7_G3, Prevotella_7, Absconditabacteria_SR1_G1, Porphyromonas, Ruminococcaceae_UCG_014, Prevotella, Peptostreptococcus, Prevotella_2, Alloprevotella, Parvimonas, Solobacterium and Eubacterium_nodatum_group in saliva were statistically more abundant in the third trimester than those in the preconception period (all P<0.05). (2) The third-trimester Shannon index was lower among those with lower income [5.44 (5.08-5.77) vs 5.75 (5.44-6.12), U=219.00, P=0.029] and those with gargle habit after meal or dessert [5.36 (4.91-5.48) vs 5.72 (5.44-6.05), U=374.00, P=0.046]. Conclusions:The features of oral microbiota vary in women during the preconception period and the third trimester. There is a significant increase in the abundance of oral pathogenic and opportunistic bacteria in the third trimester.

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.
Child ; Chromosome Deletion ; Chromosomes ; Chromosomes, Human, Pair 2 ; Humans ; In Situ Hybridization, Fluorescence ; Karyotyping ; Male ; Translocation, Genetic

Objective To explore the clinical characteristics,gene mutations,diagnosis and treatment of chil-dren with dopa-responsive dystonia due to tyrosine hydroxylase(TH)deficiency.Methods Five patients(3 boys and 2 girls)with dopa-responsive dystonia due to TH deficiency were diagnosed and followed up from January 2002 to October 2017.The clinical manifestations,laboratory findings,treatment and TH gene mutations associated with TH defi-ciency were analyzed.Results Five patients came from different families.They had the onset at the age of 8 months to 20 months with dystonia,paroxysmal muscular hypertonia and normal intelligence or mild mental retardation.All of them had been misdiagnosed as cerebral palsy.Two cases with floppy limbs presented with fatigue and tremor.One case with floppy limbs presented with seizures. Complex heterozygous mutations were found in TH gene of all patients,which helped to confirm the diagnosis.Eight mutations were identified in TH gene.Six of them were reported.Two novel muta-tions,c.1077C>A(p.C359X)and c.1228C>T(p.R410C)were detected.After the treatment by levodopa[2.2-5.4 mg/(kg·d)],significant improvement was observed.Three patients recovered their intellectual and motor activi-ties.Two patients were dramatically improved but with slightly uncoordinated movements.Conclusion The patients of dopa-responsive dystonia due to TH deficiency usually have the onset around one year of age with almost normal inte-lligence,motor retardation and dystonia.The patients are likely misdiagnosed as cerebral palsy.The treatment with levo-dopa can dramatically improve the symptoms.The etiological diagnosis is very important.

Objective The neuronal ceroid lipofuscinosis (CLN are a group of severe lysosomal storage diseases.The patients present with clinically and genetically heterogeneous neurodegenerative disorders.This study aims to investigate the clinical characteristics and the gene mutations of a rare Chinese family with 3 siblings affected by CLN7.Methods The proband,a 5-year-old girl,visited us because of intermittently seizures and mental retardation for 2 years and a half in December,2015.Clinical investigation,brain magnetic resonance imaging(MRI),biochemical and the gene analysis were performed for the etiological study.Results The proband had seizures at the age of 2 and a half years,with the progressive motor deterioration,speech disturbance,mental regression and vision loss.Her brain MRI showed diffusive cerebral atrophy.The blood aminoacids,acylcarnitine and urine organic acid profiles were normal.Lysosomal palmitoyl protein thioesterase and tripeptidyl peptidase activities of peripheral leukocytes were normal.A compound heterozygous mutation of c.1351-1G ＞ A and c.300T ＞ G was detected on her MFSD8 gene,supporting the diagnosis of CLN7.Both of the 2 mutations were novel.Each of her parents carried one of the mutations.Two brothers of the proband had similar clinical process.Her elder brother died at the age of 7 due to severe encephalopathy of unknown etiology.The younger brother showed dyskinesia from the age of 2 years and seizures from the age of 4 years.A compound heterozygous mutation on MFSD8 gene,c.1351-1G ＞ A and c.300T ＞ G,was found from the younger brother,as same as the proband.Conclusions CLN7 is a rare disorder of CLN.In this study,the diagnosis of the 3 siblings with similar clinical process were much delayed.Gene analysis was key for the diagnosis.Two novel mutations were found on MFSD8 of the family.There is still no effective treatment for neurol ceroid lipofuscinosis.The prognosis is poor.Based on the mutation diagnosis,prenatal diagnosis for the next sibling is possible to the prevention of the disease.

Objective: To study the clinical characteristics, methods of diagnosis and treatment of hyperornithinemia-hyperammonemia- homocitrullinuria (HHH) syndrome. Method: From July 2011 to August 2016, 3 Chinese patients with HHH syndrome were enrolled in this study. The clinical course, biochemical features, brain MRI findings, and gene mutations were analyzed. Result: The three patients′ age at onset of symptoms was 3 months to 7 years, and the age of diagonosis was 3 years and 10 months to 9 years and 10 months. All of them presented with intolerance to protein-rich foods from the infant period, development retardation and abnormal posture. Case 1 and 2 had moderate mental retardation. Serum ammonia 25-276 μmol/L (reference range<60 μmol/L), alanine aminotransferase (ALT) 20-139 IU/L (reference range 9-50 IU/L), ornithine 29.12-99.44 μmol/L(reference range 15-100 μmol/L), urinary orotic acid 1.49-29.75 mmol/mol Cr (reference range 0-7 mmol/mol Cr), uracil 6.09-103.97 mmol/mol Cr (reference range 0-1.5 mmol/mol Cr). The cranial MRI revealed lesions in the basal ganglia, abnormal white matter signal, progressive demyelination and cerebral atrophy. On their SLC25A15 gene, a novel homozygous missense mutation c. 416A>G (p.E139G) was identified in case 1, a known pathogenic homozygous nonsense mutation c. 535C>T was found in case 2 and 3. Liver transplantation had been performed when case 1 was 6 years old. Significant improvements were observed in dietary habit, mental and motor functions, and biochemical parameters. After the dietary intervention with the supplements of arginine, L-carnitine, case 2 was improved, spastic paraplegia of case 3 had no mitigation. Liver transplant was recommended. Conclusion HHH syndrome has an aversion to protein-rich food, and the patients have recurrent vomiting and progressive neurological dysfunction. Clinical diagnosis of HHH syndrome is difficult and patients may present with incomplete biochemical phenotype. The genetic analysis is key for the diagnosis. Depending on their condition, individuals with HHH syndrome can be treated with a low-protein diet, drugs and liver transplantation.

Objective To explore the clinical features and genetic etiology of children with cystinuria with onset of kidney stone. Methods The clinical data of 3 children with cystinuria with onset of kidney stone and the gene analysis results of SLC3A1 and SLC7A9 by PCR sequencing were retrospectively analyzed.Results Three male children were from three unrelated families, kidney stone were presented in 2 cases at 1 year old and 1 case at 14 years old. The blood amino acid spectrum was normal in all 3 cases, while the free carnitine were decreased. The urinary amino acid spectrum indicated that cystine, ornithine, arginine,and threonine increased.Gene analysis confirmed that 1 case had homozygous mutations of SLC7A9 gene c.325G>A, and his parents were carriers of c.325G>A heterozygous mutation;other 2 cases had heterozygous mutations of SLC3A1 gene, c.1365delG and c.1113C>A heterozygous mutation in one case, and c.1897_1898insTA and c.1093C>T heterozygous mutation in one case, and their parents were heterozygous mutation carriers. After treatment with potassium citrate and L-carnitine, the conditions were improved in all cases. Conclusions Inherited metabolic disease should be considered for children with kidney stone. Urine amino acid analysis and gene detection are important methods for the diagnosis of cystinuria.