Kinesin family member 12-related hepatopathy: A generally indolent disorder with elevated gamma-glutamyl-transferase activity.

Exome sequencing (ES) has identified biallelic kinesin family member 12 (KIF12) mutations as underlying neonatal cholestatic liver disease. We collected information on onset and progression of this entity. Among consecutively referred pediatric patients at our centers, diagnostic ES identified 4 patients with novel, biallelic KIF12 variants using the human GRCh38 reference sequence, as KIF12 remains incompletely annotated in the older reference sequence GRCh37. A review of these and of 21 reported patients with KIF12 variants found that presentation with elevated serum transaminase activity in the context of trivial respiratory infection, without clinical features of liver disease, was more common (n = 18) than manifest cholestatic disease progressing rapidly to liver transplantation (LT; n = 7). Onset of liver disease was at age <1 year in 15 patients; LT was more common in this group. Serum gamma-glutamyl transpeptidase activity (GGT) was elevated in all patients, and total bilirubin was elevated in 15 patients. Liver fibrosis or cirrhosis was present in 14 of 18 patients who were biopsied. The 16 different pathogenic variants and 11 different KIF12 genotypes found were not correlated with age of onset or progression to LT. Identification of biallelic pathogenic KIF12 variants distinguishes KIF12-related disease from other entities with elevated GGT.

Neonatal sclerosing cholangitis with novel mutations in DCDC2 (doublecortin domain-containing protein 2) in Chinese children.

Background: Neonatal sclerosing cholangitis (NSC) is a rare and severe autosomal recessive inherited liver disease with mutations in DCDC2, commonly requiring liver transplantation (LT) for decompensated biliary cirrhosis in childhood. Methods: The information of four Chinese patients with NSC caused by mutations in DCDC2 from Children's Hospital of Fudan University were gathered. The four patients' clinicopathological and molecular features were summarized by clinical data, liver biopsy, immunohistochemical, and molecular genetic analysis. Results: All patients presented with jaundice, hepatosplenomegaly, hyperbilirubinemia and bile embolism, and high serum γ-glutamyl transferase activity (GGT). Liver biopsies revealed varying degrees of bile duct hyperplasia, portal-tract inflammation, and/or fibrosis. Whole-exome sequencing (WES) found novel heterozygous variants of c.1024-1G > T /p.? and c.544G > A /p. Gly182Arg in the DCDC2. Conclusion: This study expands the genetic spectrum of DCDC2 in NSC.

Updated clinical and glycomic features of mannosyl-oligosaccharide glucosidase deficiency: Two case reports.

BACKGROUND: Mannosyl-oligosaccharide glucosidase (MOGS) deficiency is an extremely rare type of congenital disorder of glycosylation (CDG), with only 12 reported cases. Its clinical, genetic, and glycomic features are still expanding. Our aim is to update the novel clinical and glycosylation features of 2 previously reported patients with MOGS-CDG. CASE SUMMARY: We collected comprehensive clinical information, and conducted the immunoglobulin G1 glycosylation assay using nano-electrospray ionization source quadruple time-of-flight mass spectrometry. Novel dysmorphic features included an enlarged tongue, forwardly rotated earlobes, a birth mark, overlapped toes, and abnormal fat distribution. Novel imaging findings included pericardial effusion, a deep interarytenoid groove, mild congenital subglottic stenosis, and laryngomalacia. Novel laboratory findings included peripheral leukocytosis with neutrophil predominance, elevated C-reactive protein and creatine kinase, dyslipidemia, coagulopathy, complement 3 and complement 4 deficiencies, decreased proportions of T lymphocytes and natural killer cells, and increased serum interleukin 6. Glycosylation studies showed a significant increase of hypermannosylated glycopeptides (Glc3Man7GlcNAc2/N2H10 and Man5GlcNAc2/N2H5) and hypersialylated glycopeptides. A compensatory glycosylation pathway leading to an increase in Man5GlcNAc2/N2H5 was indicated with the glycosylation profile. CONCLUSION: We confirmed abnormal glycomics in 1 patient, expanding the clinical and glycomic spectrum of MOGS-CDG. We also postulated a compensatory glycosylation pathway, leading to a possible serum biomarker for future diagnosis.

Neonatal cholestasis is an early liver manifestation of children with acid sphingomyelinase deficiency.

BACKGROUND: Patients with acid sphingomyelinase deficiency (ASMD) may be referred to a hepatologist for liver manifestations. This study summarized the liver manifestations of patients with ASMD in the early disease course. METHODS: This study enrolled ASMD patients diagnosed by genetic tests between July 2016 and December 2020 in a national pediatric liver center. The significance of low High-density lipoprotein cholesterol (HDL-C) for aid diagnosis of ASMD in infancy was explored by reviewing 160 consecutive infants with liver manifestations, who underwent both genetic tests and lipid profile studies, between January 2020 and December 2020. RESULTS: A total of 7 patients were diagnosed as ASMD, and 10 known disease-causing variants were identified. Hepatosplenomegaly, elevated transaminases, and liver foam cells were observed in all the 7 patients at age ranging from 4 to 31 months. Low HDL-C was detected in 5 patients, cherry red spot in 4 patients, development delay in 3 patients, and interstitial lung diseases in 1 patient. Three ASMD patients developed cholestasis around 1 month of age, and bilirubin levels normalized at age ranging from 3 to 10 months. They had persistently elevated transaminases and hepatosplenomegaly, and died within 4 years of age. Among the 160 infants with liver manifestations, 125 (78.1%) had low HDL-C. Fifty-four had both low HDL-C and splenomegaly, including 48 cholestatic infants, but only 1 (1.9%, 1/54) infant without cholestasis was diagnosed as ASMD. CONCLUSIONS: ASMD can manifest as neonatal cholestasis in the early disease course. Cholestasis is a pitfall when low HDL-C is used for aid diagnosis of ASMD in infants with splenomegaly.

Defining pathogenicity of NOTCH2 variants for diagnosis of Alagille syndrome type 2 using a large cohort of patients.

BACKGROUND AND AIMS: Alagille syndrome (ALGS) type 2 caused by mutations in NOTCH2 has genotypic and phenotypic heterogeneity. Diagnosis in some atypical patients with isolated hepatic presentation could be missed. METHODS: Using 2087 patients with paediatric liver manifestations, NOTCH2 allele frequencies, in-silico prediction, protein domains and clinical features were analysed to define the pathogenicity of NOTCH2 variants for diagnosis of ALGS type 2. RESULTS: Among 2087 patients with paediatric liver manifestations, significantly more NOTCH2 variants were absent in gnomAD in patients with elevated γ-glutamyltransferase (GGT) (p = .041). Significantly more NOTCH2 variants which were absent in gnomAD were located in protein functional domains (p = .038). When missense variants were absent in gnomAD and predicted to be pathogenic by at least three out of seven in-silico tools, they were found to be significantly associated with liver manifestations with elevated GGT (p = .003). Comparing this to patients with likely benign (LB) variants, the patients with likely-pathogenic (LP) variants have significantly more liver manifestations with elevated GGT (p = .0001). Significantly more patients with LP variants had extra-hepatic phenotypes of ALGS compared with those patients with LB variants (p = .0004). CONCLUSION: When NOTCH2 variants are absent in gnomAD, null variants and missense variants which were predicted to be pathogenic by at least three in-silico tools could be considered pathogenic in patients with high GGT chronic liver diseases.

The Presence of Vacuolated Kupffer Cells Raises a Clinical Suspicion of Niemann-Pick Disease Type C in Neonatal Cholestasis.

Early diagnosis of Niemann-Pick disease type C (NP-C) in neonatal cholestasis is still challenging because splenomegaly is non-specific and oxysterol profiling studies also have a relatively low specificity. This study explores a method for identifying infants with a high clinical suspicion of NP-C in neonatal cholestasis. We reviewed the clinical findings of 9 neonatal cholestatic infants with NP-C genetically diagnosed between January 2015 and December 2020. Seven underwent liver biopsy at ages ranging from 35 to 112 d. Foam cells were only detected in 2 (28.6%, 2/7) liver tissues obtained beyond 3 months of age. However, vacuolated Kupffer cells were detected in all 7 liver tissues. Their significance was explored by using 168 neonatal cholestatic infants, who underwent genetic tests and liver biopsy between January 2018 and December 2020. Of them, 26 detected vacuolated Kupffer cells. Six (23.1%, 6/26) were diagnosed as NP-C, comparing to none of the 142 neonatal cholestatic infants without vacuolated Kupffer cells (χ 2 = 33.983, p < 0.001). The ratio of positive diagnosis of NP-C was 31.6% (6/19) in neonatal cholestatic infants with both vacuolated Kupffer cells and splenomegaly. Therefore, we conclude that the presence of vacuolated Kupffer cells can raise a high clinical suspicion of NP-C in neonatal cholestatic infants, especially in those with splenomegaly.

TMEM199-Congenital Disorder of Glycosylation With Novel Phenotype and Genotype in a Chinese Boy.

Background: TMEM199-congenital disorder of glycosylation (TMEM199-CDG) is a rare autosomal recessive inherited disease characterized by chronically elevated serum transaminase, decreased serum ceruloplasmin, steatosis and/or fibrosis, TMEM199 mutation, reduced level of TMEM199 protein, and abnormal protein glycosylation. Methods: The information of a Chinese patient with TMEM199-CDG in the Children's Hospital of Fudan University was reviewed. The patient's clinical, pathological, and molecular features were obtained by clinical data study, liver biopsy, immunohistochemistry, and molecular genetic analysis. Results: A 4-year-old Chinese boy presented with hypertransaminasemia, hypercholesterolemia, elevated alkaline phosphatase, decreased serum ceruloplasmin and serum copper level, and coagulopathy since birth. To the best of our knowledge, novel findings included strabismus, cirrhosis by liver biopsy, reduced expression of TMEM199 by immunohistochemistry, and a frameshift variant of c.128delA/p.Lys43Argfs*25 in the TMEM199 gene. Conclusion: This case added to the phenotypic and genotypic spectrum of TMEM199-CDG.

Mycoplasma pneumoniae and Adenovirus Coinfection Cause Pediatric Severe Community-Acquired Pneumonia.

Consolidation is one complication of pediatric severe community-acquired pneumonia (SCAP) that can respond poorly to conservative medical treatment. We investigated the pathogens that cause pediatric SCAP including cases with persistent consolidation that need bronchoscopy intervention. Alveolar lavage fluid (ALF) samples collected from cases admitted to Children's Hospital of Fudan University with SCAP during January 2019 to March in 2019 were retrospectively tested by the RespiFinder 2SMART multiplex PCR (multi-PCR) assay targeting 22 respiratory pathogens. A total of 90 cases and 91 samples were enrolled; 80.0% (72/90) of the cases had pulmonary consolidation and/or atelectasis. All samples were positive with targeted pathogens tested by multi-PCR, and 92.3% (84/91) of the samples were co-detected with pathogens. Mycoplasma pneumoniae (MP) and adenovirus (ADV) as the two dominant pathogens, with the positive rates of 96.7% (88/91) and 79.1% (72/91), respectively. Most of the samples were positive with MP and ADV simultaneously. As a control, 78.0% (71/91) of the samples were positive by conventional tests (CT), in which MP had the detection rate of 63.9% (55/86) by a traditional real-time PCR assay, while ADV were positive in 13.1% (12/91) of the samples by a direct immunofluorescence assay (DFA). In cases with persistent pulmonary consolidation, the positive rates of pathogens by multi-PCR and CT were 100% (72/72) and 81.9% (59/72), respectively. There were no significant differences of MP or ADV positive rates between cases with and without pulmonary consolidation. MP and ADV most prevalent in pediatric SCAP cases required fiberscope intervention, and presented with coinfections dominantly. IMPORTANCE Pathogens that cause pediatric severe community-acquired pneumonia (SCAP) requiring bronchoscopy intervention are understudied. Through this study, we explore the etiology of SCAP form alveolar lavage fluid (ALF) samples by the RespiFinder 2SMART multi-PCR assay. It is observed that high mixed detection rates of Mycoplasma pneumoniae and adenovirus in ALF samples collected from hospitalized SCAP children experienced bronchoscopy intervention. Eighty percent of the cases had pulmonary consolidation and/or atelectasis. The presence of possible coinfection of these two pathogens might contribute to poor clinical anti-infection response. The results of this study might be helpful for the selection of clinical strategies for the empirical treatment of such pediatric SCAP cases.

Four New Cases of SLC35A2-CDG With Novel Mutations and Clinical Features.

SLC35A2-CDG is a rare type of X-linked CDG with more than 60 reported cases. We retrospectively analyzed clinical phenotypes and SLC35A2 genotypes of four cases of SLC35A2-CDG from four unrelated families of Han ethnicity in China. All patients had infantile onset epilepsies that were completely or partly resistant to multiple anti-epileptic medications or ketogenic diet. Three patients had severe developmental delay. All patients were female patients carrying de novo deleterious mutations in SLC35A2 (NM_001042498.2) gene, including one canonical splice-site mutation (c.426+1G > A), one large deletion (c.-322_c.274+1del), and two frameshift mutations leading to premature stop codon (c.781delC/p.Arg289ValfsTer88 and c.601delG/p.Ala201GlnfsTer148). Novel clinical features in some of our patients include anemia, hypertriglyceridemia, hypertonia, small ears, extra folds on earlobes, and maternal oligohydramnios or hypothyroidism during pregnancy. In one patient, concomitant Marfan syndrome was confirmed for having positive family history, carrying a heterozygous known disease-causing mutation in FBN1 gene (c.7240C > T/p.Arg2414Ter), and presence of typical features (rachnodactyly, ventrical septal defect, and mitral valve regurgitation). In conclusion, we expanded clinical phenotype and genetic mutation spectrum of SLC35A2-CDG by reporting four new cases with novel pathogenic variants and novel clinical features.

Pediatric Wilson disease presenting as acute liver failure: Prognostic indices.

BACKGROUND: Acute liver failure (ALF) can be a primary presentation of Wilson disease (WD). Mortality rates are high in WD with ALF (WDALF). Predictions of mortality in WDALF vary by model and are sometimes contradictory, perhaps because few patients are studied or WD diagnoses are questionable. AIM: To determine the outcomes among well-documented WDALF patients and assess mortality model performance in this cohort. METHODS: We reviewed the medical records of our pediatric WDALF patients (n = 41 over 6-years-old, single-center retrospective study) and compared seven prognostic models (King's College Hospital Criteria, model for end-stage liver disease/pediatric end-stage liver disease scoring systems, Liver Injury Unit [LIU] using prothrombin time [PT] or international normalized ratio [INR], admission LIU using PT or INR, and Devarbhavi model) with one another. RESULTS: Among the 41 Han Chinese patients with ALF, WD was established by demonstrating ATP7B variants in 36. In 5 others, Kayser-Fleischer rings and Coombs-negative hemolytic anemia permitted diagnosis. Three died during hospitalization and three underwent liver transplantation (LT) within 1 mo of presentation and survived (7.3% each); 35 (85.4%) survived without LT when given enteral D-penicillamine and zinc-salt therapy with or without urgent plasmapheresis. Parameters significantly correlated with mortality included encephalopathy, coagulopathy, and gamma-glutamyl transpeptidase activity, bilirubin, ammonia, and serum sodium levels. Area under the receiver operating curves varied among seven prognostic models from 0.981 to 0.748 with positive predictive values from 0.214 to 0.429. CONCLUSION: WDALF children can survive and recover without LT when given D-penicillamine and Zn with or without plasmapheresis, even after enlisting for LT.

Biallelic loss-of-function ZFYVE19 mutations are associated with congenital hepatic fibrosis, sclerosing cholangiopathy and high-GGT cholestasis.

BACKGROUND: For many children with intrahepatic cholestasis and high-serum gamma-glutamyl transferase (GGT) activity, a genetic aetiology of hepatobiliary disease remains undefined. We sought to identify novel genes mutated in children with idiopathic high-GGT intrahepatic cholestasis, with clinical, histopathological and functional correlations. METHODS: We assembled a cohort of 25 children with undiagnosed high-GGT cholestasis and without clinical features of biliary-tract infection or radiological features of choledochal malformation, sclerosing cholangitis or cholelithiasis. Mutations were identified through whole-exome sequencing and targeted Sanger sequencing. We reviewed histopathological findings and assessed phenotypical effects of ZFYVE19 deficiency in cultured cells by immunofluorescence microscopy. RESULTS: Nine Han Chinese children harboured biallelic, predictedly complete loss-of-function pathogenic mutations in ZFYVE19 (c.314C>G, p.S105X; c.379C>T, p.Q127X; c.514C>T, p.R172X; c.547C>T, p.R183X; c.226A>G, p.M76V). All had portal hypertension and, at liver biopsy, histopathological features of the ductal plate malformation (DPM)/congenital hepatic fibrosis (CHF). Four children required liver transplantation for recurrent gastrointestinal haemorrhage. DPM/CHF was confirmed at hepatectomy, with sclerosing small-duct cholangitis. Immunostaining for two primary-cilium axonemal proteins found expression that was deficient intraluminally and ectopic within cholangiocyte cytoplasm. ZFYVE19 depletion in cultured cells yielded abnormalities of centriole and axoneme. CONCLUSION: Biallelic ZFYVE19 mutations can lead to high-GGT cholestasis and DPM/CHF in vivo. In vitro, they can lead to centriolar and axonemal abnormalities. These observations indicate that mutation in ZFYVE19 results, through as yet undefined mechanisms, in a ciliopathy.

Concern about liver disease in children / 中华肝脏病杂志

With the economic development and living standards improvement, various chronic viral liver diseases in children is decreasing year by year, and the liver diseases related to heredity, environment and living habits is increasing. Although liver disease in children is relatively rare and is not the main cause of childhood mortality, chronic liver disease cannot be ignored for its effect on children's growth and development, mental health, quality of life and the economic burden to family or society. Therefore, more attention should be paid to the early screening, diagnosis and treatment of pediatric liver diseases, in order to delay or prevent its progression efficiently.

A novel NFIA gene nonsense mutation in a Chinese patient with macrocephaly, corpus callosum hypoplasia, developmental delay, and dysmorphic features.

BACKGROUND: NFIA gene (OMIM*600727) has been shown to be associated with a syndrome of central nervous system malformations (corpus callosum and ventriculomegaly) with or without urinary tract defects(BRMUTD) (OMIM#613735) with a low incidence. METHODS AND RESULTS:   We presented the clinical data of a 3-month-old Chinese infant with clinical features such as thin corpus callosum, ventriculomegaly, development delay, and dysmorphic features (macrocephaly, hypertelorism, slightly pointed chin, broad forehead, and large ears). Genomic DNA was extracted for Trio Whole Exome Sequencing. Preliminary genetic tests revealed one de novo heterozygous nonsense mutation c.220 C>T (p.Arg74Ter) of the NFIA gene (NM_005595). CONCLUSION: Genetic DNA sequencing is a crucial method for diagnosing BRMUTD. This approach enriches the genotype and spectrum of BRMUTD syndrome and the outcome of the patient.

Glycogen storage disease type VI can progress to cirrhosis: ten Chinese patients with GSD VI and a literature review.

Objectives The aim of our study is to systematically describe the genotypic and phenotypic spectrum of Glycogen storage disease type VI (GSD VI), especially in Chinses population.  Methods We retrospectively analyzed ten Chinese children diagnosed as having GSD VI confirmed by next generation sequencing in Children's Hospital of Fudan University and Jinshan Hospital of Fudan University. We described the genotypic and phenotypic spectrum of GSD VI through the clinical and genetic data we collected. Moreover, we conducted a literature review, and we compared the genotypic and phenotypic spectrum of GSD VI between Chinese population and non Chinese population.  Results For the first time, we found that four Chinese patients showed cirrhosis in liver biopsy characterized by the formation of regenerative nodules. In addition, c.772+1G>A and c.1900G>C, p.(Asp634His) were recurrent in three Chinese families and four European families respectively indicating that the genotypic spectrum of PYGL gene may vary among the population. Furthermore, we identified seven novel variants in PYGL gene.  Conclusions Our study enriched the genotypic and phenotypic spectrum of GSD VI, and provided a new clue for management of GSD VI.

NBAS disease: 14 new patients, a recurrent mutation, and genotype-phenotype correlation among 24 Chinese patients.

AIM: Neuroblastoma amplified sequence (NBAS)-associated disease has a wide phenotypic spectrum, including infantile liver failure syndrome type 2 (ILFS2, OMIM #616483), short stature with optic nerve atrophy and Pelger-Huët anomaly (SOPH) syndrome (OMIM #614800), and a combined phenotype overlapping ILFS2 and SOPH syndrome. The mutation spectra of NBAS and its genotype-phenotype correlation among Chinese were not clear. METHODS: Clinical and genetic data were retrospectively collected from the medical charts of patients with biallelic NBAS mutations, as well as from Chinese patients in previously published reports. RESULTS: Fourteen new patients were identified, including 10 novel mutations: c.648-1G>A, c.2563_c.2577+5del/p.His855_Gln859del, c.3115C>T/p.Gln1039Ter, c.3284G>A/p.Trp1095Ter, c.2570C>T/p.Ala857Val, c.6859G>T/p.Asp2287Tyr, c.1028G>A/p.Ser343Asn, c.1177_1182delinsAGATAGA/p.Val393ArgfsTer2, c.3432_3435dupCAGT/p.Ala1146GlnfsTer14, and c.680_690dupACTGTTTCAGC/p.Phe231ThrfsTer35. All 14 patients presented as fever-triggered liver injury, including nine patients that satisfied the criteria of acute liver failure (ALF) in whom c.3596G>A/p.Cys1199Tyr occurred five times. Nine patients had extrahepatic manifestations including short stature, skeletal abnormalities, intellectual disability, ophthalmic abnormalities, low levels of serum immunoglobulins, facial dysmorphism, and cardiac abnormalities. Ten other Chinese patients were collected through a review of published works. Genotype-phenotype analysis in 24 Chinese patients revealed that the percentage of ALF patients with variants in the Sec39 domain was significantly higher than that in the C-terminal (100% vs. 12.5%, P = 0.000), and the percentage of multi-organ/system involvement in patients with variants in the Sec39 domain was significantly lower than that in the C-terminal (40% vs. 100%, P = 0.0128). CONCLUSIONS: We reported 14 new patients, 10 novel mutations, and a unique recurrent mutation. Correlation analysis indicated that the domain of missense and non-frameshift insertion/deletion mutations in NBAS protein is related to phenotype among Chinese patients.

An infant presenting with extreme hypertriglyceridemia diagnosed as glycogen storage disease type Ia.

Background Marked hypertriglyceridemia in infancy is extremely rare. Patients with severe hypertriglyceridemia in early life may be unmasked by a primary or secondary cause. Case presentation A female infant was born in a good condition with normal Apgar scores. No special clinical symptoms and signs had been found within the first two months of life. Poor oral intake and failure to thrive were two main clinical manifestations when she was referred to our hospital at the age of 3.5 months. The milky serum was the only one characteristic presentation. Laboratory testing showed extremely high level of triglycerides, cholesterol and lactate. Many other laboratory indexes cannot be detected because of severe hyperlipemic samples. Multi-gene panel testing for 249 genes about genetic and metabolic liver disease were performed. Gene analysis revealed a G6PC gene deficiency. The patient was a homozygote for c.248G > A, p.R83H and her parents were both the heterozygotes. The infant had been diagnosed as glycogen storage disease type Ia. Conclusions We report an infant presenting with extreme hypertriglyceridemia diagnosed as glycogen storage disease type Ia by genetic testing. The gene panel can be used to confirm the diagnosis and delineate the exact type of glycogen storage disease, which could ultimately really help to reduce unnecessary tests and invasive examinations. Serum lipid should be close monitoring in order to prevent the complications and improve the prognosis.

Novel NGLY1 gene variants in Chinese children with global developmental delay, microcephaly, hypotonia, hypertransaminasemia, alacrimia, and feeding difficulty.

NGLY1 deficiency is the first and only autosomal recessive congenital disorder of N-linked deglycosylation (NGLY1-CDDG). To date, no patients with NGLY1 deficiency has been reported from mainland China or East Asia in English literature. Here, we present six patients with a diagnosis of NGLY1-CDDG on the basis of clinical phenotype, genetic testing, and functional studies. We retrospectively analyzed clinical phenotypes and NGLY1 genotypes of six cases from four families. Informed consent was obtained for diagnosis and treatment. In-silico tools and in vitro enzyme activity assays were used to determine pathogenicity of NGLY1 varaints. All patients had typical features of NGLY1-CDDG, including global developmental delay, microcephaly, hypotonia, hypertransaminasemia, alacrimia, and feeding difficulty. Dysmorphic features found in our patients include flat nasal bridge, loose and hollow cheeks, short stature, malnutrition, and ptosis. Pachylosis could be a novel cutaneous feature that may be explained by lack of sweat. We found three novel variants, including one missense (c.982C > G/p.Arg328Gly), one splice site (c.1003+3A > G), and one frame-shift (c.1637-1652delCATCTTTTGCTTATAT/p.Ser546PhefsTer) variant. All mutations were predicted to be disease causing with in-silico prediction tools, and affected at least one feature of gene splicing. Protein modeling showed missense variants may affect covalent bonding within the protein structure, or interrupt active/binding amino-acid residues. In vitro studies indicated that proteins carrying missense variants (p.Arg328Gly and p.Tyr342Cys) lost the enzyme activity. We expanded clinical phenotype and genetic mutation spectrum of NGLY1-CDDG by reporting six cases, three novel variants, and novel clinical features from mainland China.

Molecular findings in children with inherited intrahepatic cholestasis.

BACKGROUND: Genetic defects account for a substantial proportion of pediatric cholestasis. This study explored the molecular findings in a large cohort of Chinese patients with inherited cholestasis. METHODS: Between January 2012 and June 2016, 809 Chinese pediatric patients with suspected inherited intrahepatic cholestasis were evaluated by Sanger sequencing and/or panel sequencing. RESULTS: Of the 809 patients, 273 (33.7%) obtained a genetic diagnosis. The rate of positive genetic diagnosis in patients with disease onset at 0-3 month of age was higher than that in patients with disease onset at 4 month of age or later. There were 17 distinct genetic defects diagnosed. The top 4 resulted from mutations in SLC25A13 (44.3%), JAG1 (24.5%), ABCB11 (11.0%), and ATP8B1 (5.9%). All 17 genetic disorders were diagnosed in patients with disease onset at 0-3 months of age; but only 5 were diagnosed in patients with disease onset beyond 4 months of age. A total of 217 distinct pathogenic variants, including 41 novel variants, were identified. Ten recurrent mutations were detected in SLC25A13, ATP8B1, and CYP27A1. They accounted for 48.2% of the total 477 mutant alleles. CONCLUSIONS: There were 17 distinct genetic disorders diagnosed in Chinese pediatric patients with inherited cholestasis.

Novel missense mutation in VPS33B is associated with isolated low gamma-glutamyltransferase cholestasis: Attenuated, incomplete phenotype of arthrogryposis, renal dysfunction, and cholestasis syndrome.

The typical phenotype of arthrogryposis, renal dysfunction, and cholestasis (ARC) syndrome involves three cardinal symptoms as the name describes, harboring biallelic mutations on VPS33B or VIPAS39. Except for ARC syndrome, low gamma-glutamyltransferase (GGT) cholestasis often implies hereditary hepatopathy of different severity; however, some remain undiagnosed. Several monogenic defects typically with multiorgan manifestations may only present liver dysfunction at times, such as DGUOK defect and AGL defect. Previously, four VPS33B mutated cases were reported without arthrogryposis, or with less severe symptoms and longer lifespan, indicating the possibility of incomplete ARC phenotype of isolated hepatopathy. So we retrospectively reviewed all patients with confirmed VPS33B/VIPARS39 defect in our center and identified three presenting isolated low-GGT cholestasis with intractable pruritus. Distinguished from others with typical ARC phenotype, these patients did not suffer the other two typical characteristics, survived much longer, and shared a novel missense VPS33B variation c.1726T>C, p.Cys576Arg, causing declined protein expression and abolished interaction with VIPAS39 in-vitro. Serum bile acid profiles of our VPS33B/VIPAS39 mutated patients revealed similar changes to primary defect of bile salt export pump, among which those with isolated cholestasis phenotype had a higher level of total secondary bile acids than that with typical ARC phenotype, indicating the partial residual function of VPS33B.

Novel Melanocortin 2 Receptor Variant in a Chinese Infant With Familial Glucocorticoid Deficiency Type 1, Case Report and Review of Literature.

Familial glucocorticoid deficiency type 1 (FGD1) is an autosomal recessive disorder caused by mutations in the melanocortin 2 receptor (MC2R) gene, characterized by a low or undetectable serum cortisol level and a high adrenocorticotropic hormone (ACTH) level. Clinical manifestations include hypoglycemia, seizure, skin hyperpigmentation, hyperbilirubinemia, cholestasis, and a tall stature. Some dysmorphic features such as, a prominent forehead, hypertelorism, a broad nasal bridge, and small tapering fingers, have been reported. Children with FGD1 may have other isolated endocrine abnormalities. To date, no patient with FGD1 has been reported in mainland China. Here we report on a Chinese patient with FGD1 having a novel MC2R gene variant, a mild transverse palm crease, hypertelorism, and subtle/transient endocrine abnormalities relating to all three zones of the adrenal cortex and thyroid gland. We also reviewed cases with dysmorphic features or additional endocrine abnormalities.