BACKGROUND

Newborns screened positive for Galactosemia through Expanded Newborn Screening (ENBS) with borderline levels undergo lactose challenge that requires interruption of breastfeeding temporarily then shifting to soy-based formula.

To determine the percentage of Classical Galactosemia (CGal), Non-classical Galactosemia (NCGal), probable mild variant form, and negative Galactosemia among newborns screened positive for Galactosemia who underwent lactose challenge.

This is a retrospective study. NBS records were reviewed and data were collected from January 2015 to December 2020.

Out of the 117 newborns screened positive for Galactosemia, 58 underwent lactose challenge. Majority were male, term with a birth weight of 2500-4000g and received a final disposition in 4-6 months. Fifteen patients underwent 1-week lactose challenge wherein six reached a resolution on first challenge. Majority, 35 (60.3%) were negative for Galactosemia, six (10.3%) probable mild variant Galactosemia, three (5.2%) NCGal, and no CGal were observed. Fourteen suspected cases (24.1%) are pending final disposition.

This study describes the demographics of newborns flagged for Galactosemia who underwent lactose challenge. A 1-week lactose challenge may be recommended to further detect patients who are negative for Galactosemia.

Humans ; Amino Acid Metabolism, Inborn Errors/genetics* ; Mutation, Missense ; Proline Oxidase/genetics*

OBJECTIVE: To explore the genetic basis for a child with Isolated sulfite oxidase deficiency (ISOD). METHODS: The child and her parents were subjected to targeted capture and next-generation sequencing. Pathogenicity of candidate variants was assessed based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). RESULTS: The child was found to harbor compound heterozygous variants of the SUOX gene, namely c.1200C>G (p.Tyr400*) and c.1406_1421delCCTGGCAGGTGGCTAA (p.Thr469Serfs*20), which were inherited from her mother and father, respectively. The c.1200C>G was a known pathogenic variant, while the c.1406_1421delCCTGGCAGGTGGCTAA was unreported previously and predicted to be a pathogenic variant (PVS1+PM2_Supporting +PM3) based on the guidelines from the American College of Medical Genetics and Genomics. CONCLUSION The compound c.1200C>G and c.1406_1421delCCTGGCAGGTGGCTAA variants of the SUOX gene probably underlay the pathogenesis of ISOD in this child. Above finding has expanded the spectrum of SUOX gene variants and provided molecular evidence for the clinical diagnosis and genetic counseling for this pedigree.
Child ; Female ; Humans ; Amino Acid Metabolism, Inborn Errors/genetics* ; Genetic Counseling ; Genomics ; High-Throughput Nucleotide Sequencing ; Mutation

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.
Humans ; Male ; Cardiomyopathy, Restrictive ; Computational Biology ; Diastole ; Mutation ; Phenylketonurias ; Child, Preschool

OBJECTIVE: To carry out Sanger sequencing for MMACHC gene variants among 65 Chinese pedigrees affected with combined methylmalonic aciduria and homocysteinemia, and summarize their genetic and clinical characteristics and prognosis. METHODS: Clinical characteristics of the 65 children identified with Methylmalonic acidemia and homocysteinemia at the Children's Hospital Affiliated to Zhengzhou University (Zhengzhou Children's Hospital) from April 2017 to April 2022 were selected as the study subjects. Potential variants of the MMACHC gene were detected by direct sequencing of the PCR products. RESULTS: The median age of the 65 children was 3 months (14 days to 17 years old). These included 28 cases (43.08%) from neonatal screening, 11 cases (16.92%) with a history of jaundice, and 9 cases (13.85%) with various degrees of anemia. The main clinical symptoms included development delay, slow growth, epilepsy, hydrocephalus, lethargy, feeding difficulty, regression or decline in motor ability, recurrent respiratory infections, anemia, jaundice, respiratory and heart failures, hydrocephalus, limb weakness, and hypertension. Blood and urine tandem mass spectrometry screening has revealed increase of methylmalonic acid, propionyl carnitine, propionyl carnitine/acetylcarnitine ratio, and propionyl carnitine/free carnitine ratio to various extents, and blood homocysteine was increased in all patients. The detection rate of genetic variants was 98.46% (128/130), and in total 22 types of MMACHC gene variants were detected. The most common ones have included c.609G>A (W203X) (58/128), c.658-660del (K220del) (19/128), and c.80A>G (Q27A) (16/128). Two novel variants have been identified, namely c.565C>T (p.R189C) and c.624_ 625delTG (p.A208Afs), which were respectively predicted as likely pathogenic (PM2_Supporting+PM3+PP2+PP3) and pathogenic (PVS1+PM2_Supporting+PM3+PP2) based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). Exon 4 had the highest frequency for the detection. CONCLUSION Identification of MMACHC gene variants has confirmed the diagnosis in the children, among which the c.609G>A variant has the highest frequency. Discovery of the new variants has enriched the mutational spectrum of the MMACHC gene.
Humans ; Amino Acid Metabolism, Inborn Errors/genetics* ; Hydrocephalus ; Oxidoreductases

OBJECTIVE: To explore the clinical phenotype and genetic features of two children with MEGDEL syndrome due to variants of the SERAC1 gene. METHODS: Two children who had presented at the Fujian Medical University Union Hospital respectively on July 14, 2020 and July 28, 2018 were selected as the study subjects. Clinical features and results of genetic testing were retrospectively analyzed. RESULTS: Both children had featured developmental delay, dystonia and sensorineural deafness, along with increased urine 3-methylglutaric acid levels. Magnetic resonance imaging revealed changes similar to Leigh-like syndrome. Gene sequencing revealed that both children have harbored pathogenic compound heterozygous variants of the SERAC1 gene, including c.1159C>T and c.442C>T in child 1, and c.1168C>T and exons 4~9 deletion in child 2. CONCLUSION Children with MEGDEL syndrome due to SERAC1 gene variants have variable clinical genotypes. Delineation of its clinical characteristics and typical imaging changes can facilitate early diagnosis and treatment. Discovery of the novel variants has also enriched the spectrum of SERAC1 gene variants.
Humans ; Retrospective Studies ; Metabolism, Inborn Errors ; Hearing Loss, Sensorineural/genetics* ; Dystonia ; Carboxylic Ester Hydrolases

OBJECTIVE: To explore the clinical features and genetic basis for a child with 3-methylglutaconic aciduria type VII. METHODS: A child who was diagnosed at the Gansu Provincial Maternity and Child Health Care Hospital on August 9, 2019 was selected as the study subject. Clinical data of the child, including urine gas chromatography and mass spectrometry, were collected. The child and her parents were subjected to whole exome sequencing. RESULTS: The child, a female neonate, had presented mainly with intermittent skin cyanosis, convulsions, hypomagnesemia, apnea, neutropenia after birth. Her urine 3-methylpentenedioic acid has increased to 17.53 μmol/L. DNA sequencing revealed that she has harbored compound heterozygous variants of the CLPB gene, namely c.1016delT (p.L339Rfs*5) and c.1087A>G (p.R363G), which were respectively inherited from her mother and father. Both variants were unreported previously. Based on the standards from the American College of Medical Genetics and Genomics (ACMG), the variants were respectively predicted to be pathogenic and likely pathogenic. CONCLUSION The child was diagnosed with 3-methylglutenedioic aciduria type VII. Discovery of the c.1016delT and c.1087A>G variants has enriched the mutational spectrum of the CLPB gene.
Female ; Humans ; Infant, Newborn ; Pregnancy ; Base Sequence ; Metabolism, Inborn Errors/diagnosis* ; Mutation ; Neutropenia/genetics* ; Sequence Analysis, DNA

OBJECTIVE: To explore the clinical features and genetic variant in a child with Cerebral creatine deficiency syndrome (CCDS). METHODS: A child who had presented at the Affiliated Children's Hospital of Fudan University on March 5, 2021 was selected as the study subject. Whole exome sequencing (WES) was carried out for the child, and candidate variant was verified by Sanger sequencing. The level of creatine in the brain was determined by magnetic resonance spectroscopy. RESULTS: The patient, a 1-year-and-10-month male, had presented with developmental delay and epilepsy. Both his mother and grandmother had a history of convulsions. MRS showed reduced cerebral creatine in bilateral basal ganglia and thalamus. The child was found to harbor a hemizygous splicing variant of the SLC6A8 gene, namely c.1767+1_1767+2insA, which may lead to protein truncation. The variant was not found in the public databases. Both his mother and grandmother were heterozygous carriers for the same variant. CONCLUSION The hemizygous c.1767+1_1767+2insA variant of the SLC6A8 gene probably underlay the CCDS in this child. Discovery of the novel variant has also expanded the mutational spectrum of the SLC6A8 gene.
Humans ; Male ; Amino Acid Metabolism, Inborn Errors ; Brain ; Creatine/genetics* ; Heterozygote ; Mothers ; Nerve Tissue Proteins ; Plasma Membrane Neurotransmitter Transport Proteins/genetics* ; Infant

OBJECTIVES: To summarize the clinical characteristics and nutrition therapy for children with lysinuric protein intolerance (LPI). METHODS: The clinical manifestations, laboratory test results and enteral nutrition treatment in a girl with LPI diagnosed in Xiangya Hospital, Central South University were retrospective analyzed. Additionally, the data of the children with LPI reported in China and overseas were reviewed. RESULTS: A case of 4-year-old girl was presented, who exhibited significant gastrointestinal symptoms, such as chronic abdominal distension, prolonged diarrhea, recurrent pneumonia, and limited growth. She had a poor response to anti-infection treatment. After receiving enteral nutrition therapy, she did not experience any gastrointestinal discomfort, and there were improvements in the levels of hemoglobin, albumin, and blood ammonia. Unfortunately, due to serious illness, she declined further treatment and later passed away. A total of 92 cases of pediatric patients with LPI have been reported to date, including one case reported in this study. Most children with LPI experienced disease onset after weaning or introduction of complementary foods, presenting with severe digestive system symptoms, malnutrition, and growth retardation. It is noteworthy that only 50% (46/92) of these cases received nutritional therapy, which effectively improved their nutritional status. Among the 92 children, 8 (9%) died, and long-term follow-up data were lacking in other reports. CONCLUSIONS LPI often involves the digestive system and may result in growth restriction with a poor prognosis. Nutritional therapy plays a crucial role in the comprehensive treatment of LPI.
Child, Preschool ; Female ; Humans ; Amino Acid Metabolism, Inborn Errors/therapy* ; Enteral Nutrition/methods* ; Malnutrition ; Retrospective Studies

OBJECTIVES: To investigate genotype-phenotype characteristics and long-term prognosis of neonatal carbamoyl phosphate synthetase 1 (CPS1) deficiency among children through newborn screening in Zhejiang province. METHODS: The clinical and follow-up data of children with CPS1 deficiency detected through neonatal screening and confirmed by tandem mass spectrometry and genetic testing in Zhejiang Province Newborn Disease Screening Center from September 2013 to August 2023 were retrospectively analyzed. RESULTS: A total of 4 056 755 newborns were screened and 6 cases of CPS1 deficiency were diagnosed through phenotypic and genetic testing. Ten different variations of <i>CPS1i> genewere identified in genetic testing<i>,i> including 2 known pathogenic variations (c.2359C>T and c.1549+1G>T) and 8 unreported variations (c.3405-1G>T, c.2372C>T, c.1436C>T, c.2228T>C, c.2441G>A, c.3031G>A, c.3075T>C and c.390-403del). All patients had decreased citrulline levels (2.72-6.21 μmol/L), and varying degrees of elevated blood ammonia. The patients received restricted natural protein intake (special formula), arginine and supportive therapy after diagnosis, and were followed-up for a period ranging from 9 months to 10 years. Three patients experienced hyperammonemia, and one patient each had attention deficit hyperactivity disorder, transient facial twitching and increased muscle tone. One patient died, while the other five surviving patients had normal scores of the Ages & Stages Questionnaires (ASQ) and Griffiths Development Scales up to the present time; 4 cases had combined height or weight lag and one case was normal in height and weight. CONCLUSIONS Low citrulline levels and hyperammonemia are common in CPS1 deficiency patients in Zhejiang. Most gene variants identified were specific to individual families, and no hotspot mutations were found. Early diagnosis through newborn screening and following standardized treatment can significantly improve the prognosis of the patients.
Child ; Humans ; Infant, Newborn ; Carbamoyl-Phosphate Synthase I Deficiency Disease/therapy* ; Neonatal Screening ; Follow-Up Studies ; Hyperammonemia ; Citrulline/genetics* ; Retrospective Studies ; Mutation