Clinical characteristics and genetic analysis of a child with Galactosemia due to compound heterozygous variants of GALT gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and genetic basis of a child with Galactosemia.@*METHODS@#A child who had presented at the Children's Hospital Affiliated to Zhengzhou University on November 20, 2019 was selected as the study subject. Clinical data of the child was collected. Whole exome sequencing was carried out for the child. Candidate variants were validated by Sanger sequencing.@*RESULTS@#Clinical manifestations of the child have included anemia, feeding difficulty, jaundice, hypomyotonia, abnormal liver function and coagulation abnormality. Tandem mass spectrometry showed increased citrulline, methionine, ornithine and tyrosine. Urine organic acid analysis showed increased phenyllactic acid, 4-hydroxyphenylacetic acid, 4-hydroxyphenyllactic acid, 4-hydroxyphenylpyruvate and N-acetyltyrosine. Genetic testing revealed that the child has harbored compound heterozygous variants of the GALT gene, namely c.627T>A (p.Y209*) and c.370G>C (p.G124R), which were respectively inherited from her healthy parents. Among these, c.627T>A (p.Y209*) was known as a likely pathogenic variant, while c.370G>C (p. G124R) was unreported previously and also predicted as a likely pathogenic variant(PM1+PM2_Supporting+PP3_Moderate+PPR).@*CONCLUSION@#Above discovery has expanded the spectrum of the GALT gene variants underlying Galactosemia. Patients with thrombocytopenia, feeding difficulties, jaundice, abnormal liver function and coagulation abnormality without obvious causes should be analyzed by screening of metabolic diseases in combination with genetic testing.

Analysis of clinical characteristics and ACADM gene variants in four children with Medium chain acyl-CoA dehydrogenase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of four patients with medium-chain acyl-CoA dehydrogenase deficiency (MCADD).@*METHODS@#Four children who had presented at the Children's Hospital Affiliated to Zhengzhou University between August 2019 and August 2021 were selected as the study subjects. Clinical data of the children were collected. The children were subjected to whole exome sequencing (WES).@*RESULTS@#All of the four children were diagnosed with MCADD. Blood amino acid and ester acyl carnitine spectrum test showed that the concentration of octanoyl carnitine (C8) was significantly increased. The main clinical manifestations included poor mental response (3 cases), intermittent diarrhea with abdominal pain (1 case), vomiting (1 case), increased transaminase (3 cases), and metabolic acidosis (2 cases). Five variants were identified by genetic testing, among which c.341A>G (p.Y114C) was unreported previously. Three were missense variants, one was frameshift variant and one was splicing variant.@*CONCLUSION@#The clinical heterogeneity of MCADD is obvious, and the severity of the disease may vary. WES can assist with the diagnosis. Delineation of the clinical symptoms and genetic characteristics of the disease can facilitate early diagnosis and treatment of the disease.

Genetic analysis of a child with restricted cardiomyopathy and phenylketonuria and a literature review / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical and genetic characteristics of a child with restricted cardiomyopathy (RCM) and phenylketonuria (PKU), and summarize the clinical characteristics and genetic diversity of RCM in children through a literature review.@*METHODS@#A child with RCM in conjunct with PKU who was admitted to the Children's Hospital Affiliated to Zhengzhou University in June 2020 due to edema of eyelids and lower limbs for 1 year and aggravation for over 1 month was selected as the study subject. Relevant clinical data were collected. Peripheral blood samples of the child and his parents were collected for whole exome sequencing (WES). Candidate variants were validated by Sanger sequencing and bioinformatic analysis. Childhood, TNNI3 gene and restricted cardiomyopathy were used as the keywords to search the Wanfang data knowledge service platform, Chinese Journal Full-text database and PubMed database, and the search period was limited to from the time of establishment till August 2022. Clinical manifestations and characteristics of the TNNI3 gene variants were summarized.@*RESULTS@#The child, a 2-year-old-and-4-month-old male, had normal intelligence, facial features and normal hair and skin color, but his motor and physical development was delayed, in addition with edema of bilateral eyelids and lower limbs. The results of WES and Sanger sequencing revealed that he has harbored compound heterozygous variants of the PAH gene, namely c.331C>T (p.R111X) and c.940C>A (p.P341T), which were inherited from his father and mother, respectively. In addition, he has also harbored a de novo heterozygous variant of c.508C>T (p.R170W) of the TNNI3 gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the TNNI3: c.508C>T (p.R170W) was classified as a pathogenic variant (PS2+PS4+PM2_Supporting+PM5), PAH: c.331C>T (p.R111X) as a pathogenic variant (PVS1+PM2_Supporting+PM3+PP4), and c.940C>A (p.P341T) as a likely pathogenic variant (PM2_Supporting+PM3+PM5+PP4). In total 30 children with RCM caused by TNNI3 gene variants were retrieved, with a male-to-female ratio of 1 : 1.55 and manifestations including heart failure, sinus rhythm, bi-atrial enlargement, ST-T wave change, ventricular restricted filling, and decreased ventricular diastolic function. In total 16 variants of the TNNI3 gene were identified, among which c.575G>A was the most common, and all cases had conformed to an autosomal dominant inheritance.@*CONCLUSION@#Phenylalanine hydroxylase deficiency and RCM are rare diseases with complex clinical manifestations. The PAH: c.331C>T (p.R111X)/c.940C>A (p.P341T) and TNNI3: c.508C>T (p.R170W) variants probably underlay the RCM and PKU in this child.

Childhood onset spinocerebellar ataxia type 2: a family report and literature review / 中华神经科杂志

Objective:To investigate the clinical characteristics, genetic characteristics and diagnosis of spinocerebellar ataxia type 2 (SCA2) patients with childhood onset.Methods:The clinical data of a SCA2 pedigree who diagnosed at Neurogenetic Metabolic Disease Clinic of Children′s Hospital Affiliated to Zhengzhou University in July 2019 were collected, and the reported cases of childhood-onset SCA2 were reviewed. The CAG repeat of ATXN2 gene was detected by polymerase chain reaction, capillary gel electrophoresis and Sanger sequencing techniques.Results:A total of 9 people in 4 generations of the family were affected, showing an autosomal dominant inheritance. The proband was a 3 years and 4 months old boy, who showed abnormal symptoms at 9 months which manifested as developmental retardation. At 1 year old, he developed progressive regression which represented neither to be amused, recognize others, stand and walk alone, nor had language development. Meanwhile, he had difficulty swallowing, long-term constipation, and a history of convulsions. His sister and mother were not yet sick. His grandmother could not walk, had slurred speech accompanied by nystagmus, and magnetic resonance imaging showed cerebellar atrophy. His granduncles and grandaunts had unstable walking and dysarthria. His great-grandfather required wheelchair to walk. This pedigree showed an autosomal dominant inheritance. One of the ATXN2 gene alleles of the proband, his sister, mother and grandmother all showed abnormal amplification with 99, 55, 44, and 43 times respectively and no inserting CAA sequence. A total of 14 literatures reported 20 cases of childhood-onset SCA2 patients who were genetically diagnosed. The majorities had onset in infancy, and few can develop into school age. The main clinical manifestations were developmental delay, dystonia or insufficiency, myoclonus or infantile spasms, motor retardation, abnormal eye movement, retinitis pigmentosa and dysphagia, while the classic cerebellar syndrome was only partially present. Abnormal rhythm was found on electroencephalogram, cerebellar atrophy on magnetic resonance imaging or CT of the head.Conclusions:This case is the youngest genetically-confirmed SCA2 patient reported in China. Reported patients usually have onset in infancy with excessive repeat sequence expansion. Their clinical characteristics are different from the classic patients and could only be diagnosed by dynamic mutation detection.

3-Hydroxy-isobutyryl-coenzyme A hydrolase deficiency: a case report and literature review / 中华神经科杂志

Objective:To analyze the characteristics of clinical manifestation, auxiliary examination and gene mutation of 3-hydroxy-isobutyryl-coenzyme A hydrolase (HIBCH) deficiency to better understand this disease.Methods:The clinical manifestations and genetic results of a patient with HIBCH deficiency were analyzed. The clinical features and genetic characteristics of HIBCH deficiency were summarized based on the literature review.Results:The proband, female, one year and four months old, was admitted to Children′s Hospital Affiliated to Zhengzhou University for “vomiting and diarrhea for 15 days, dyspnea and intermittent convulsions for 13 days after digestive tract infection”. The intelligence was normal, however, the motor development was slightly delayed before onset. Physical examination showed light coma, poor response and insensitivity to light. She also had shortness of breath, weak positive three concave signs and coarse breath sound in both lungs with sputum purrs. In addition, the muscle tension of extremities was increased. Bilateral Brudzinski′s sign, Babinski′s sign and Kernig′s sign were negative. Serum hydroxybutyryl carnitine (C4OH) was increased. Cranial magnetic resonance imaging (MRI) showed atrophy in bilateral cerebral hemispheres and abnormal symmetry signals in bilateral globus pallidus and cerebral peduncle. Novel compound heterozygous variants of HIBCH, c.489T>A (p. C163*) and c.740A>G (p. Y247C), were found in the patient, which respectively inherited from her healthy parents. Her symptoms were relieved after“cocktail”therapy and symptomatic treatment. Literature related to HIBCH deficiency published all around the world was reviewed. As a result, 17 articles, including 24 cases, had been reported. The majority of patients presented with poor feeding, dystonia and progressive motor developmental delay in early infancy. Cranial MRI showed lesions in bilateral basal ganglia. Serum C4OH concentration was elevated. And compound heterozygous or homozygous variants of HIBCH gene were found in patients with HIBCH deficiency.Conclusions:The detection of serum amino acids and acylcarnitine profiles on HIBCH deficiency was relatively specific and it was helpful to make a clear diagnosis by combining with cranial MRI and genetic tests. In this study, a case of HIBCH deficiency was confirmed, which expanded the mutation spectrum of HIBCH gene. Meanwhile, summarizing the clinical and genetic characteristics of cases reported improved understanding of HIBCH deficiency.