Identification of a novel pathogenic TBCK variant in a Chinese patient with infantile hypotonia with psychomotor retardation and characteristic facies type 3 (IHPRF3): a case report.

BACKGROUND: Infantile hypotonia with psychomotor retardation and characteristic facies type 3(IHPRF3) (OMIM #616,900) is an autosomal recessive disorder caused by biallelic pathogenic variants of the TBCK gene, and to date, this disease was reported rather limitedly in number and all described cases were Caucasians. CASE PRESENTATION: This paper reported the clinical and genetic features of a Chinese patient with IHPRF3. The patient was a 15-month-old male with global developmental delay, profound hypotonia, and typical facial dysmorphic features including mildly coarse facial appearance, hypertelorism, tented upper lip, exaggerated Cupid's bow, macroglossia and arched eyebrows. Magnetic Resonance Imaging (MRI) analysis of the brain revealed slightly widened bilateral ventricles and subarachnoid space. On genetic analysis, the patient was homozygous for a novel TBCK variant c.247C > T(p.Arg83Ter). The parents were both carriers without any positive symptoms or signs. With an extremely low frequency (0.0000082) in Exome Aggregation Consortium, the variant has not been reported in any other databases or official literatures, and was diagnosed to be pathogenic according to the American College of Medical Genetics and Genomics(ACMG) standards and guidelines. Neurorehabilitation training did not work well and the long-term prognosis remained to be observed. CONCLUSIONS: This study reported the clinical and molecular features of the first non-Caucasian patient with IHPRF3 arising from a novel homozygous TBCK mutation, which provided a novel molecular marker for the definite diagnosis of IHPRF3 patients and for its genetic counseling and prenatal diagnosis in the affected families.

Clinical characterization of NTCP deficiency in paediatric patients : A case-control study based on SLC10A1 genotyping analysis.

Na+ -taurocholate cotransporting polypeptide deficiency (NTCPD) is a newly described disorder arising from biallelic mutations of the SLC10A1 gene. As a result of a lack of compelling evidence from case-control studies, its genotypic and phenotypic features remain open for in-depth investigation. This study aimed to explore the genotypic and clinical phenotypic characteristics of paediatric patients with NTCPD. The SLC10A1 genotypes of all NTCPD patients were confirmed by screening for the prevalent variant c.800C>T and Sanger sequencing when necessary. The clinical presentations and laboratory changes were collected, reviewed and analysed, and then qualitatively and quantitatively compared with the relevant controls. A total of 113 paediatric NTCPD patients were diagnosed while c.374dupG and c.682_683delCT were detected as two novel pathogenic mutations. Hypercholanemia was observed in 99.12% of the patients. Indirect hyperbilirubinemia in affected neonates exhibited higher positive rates in comparison to controls. Moreover, transient cholestatic jaundice, elevated liver enzymes and 25-hydroxyvitamin D (Vit D) deficiency during early infancy were more commonly observed in patients than in controls. All NTCPD patients exhibited favourable clinical outcomes as a result of symptomatic and supportive treatment. The findings enriched the SLC10A1 mutation spectrum and provided comprehensive insights into the phenotypic characteristics of NTCPD. NTCPD should be considered and SLC10A1 gene should be analysed in patients with above age-dependent clinical features. Furthermore, over investigation and intervention should be avoided in the management of NTCPD patients.

[Clinical features and LAMA2 mutations of patients with congenital muscular dystrophy type 1A: a case report and literature review].

Biallelic pathogenic mutations of the LAMA2 gene result in congenital muscular dystrophy type 1A (CMD1A). The patient in this study was a boy aged 19 months, with the clinical manifestations of motor development delay and increases in the serum levels of creatine kinase, aminotransferases, and lactate dehydrogenase. Genetic analysis showed that the patient had compound heterozygous mutations in the LAMA2 gene, among which c.7147C>T (p.Ala2383Ter) from his mother was a known nonsense mutation, and c.8551_8552insAA (p.Ile2852ArgfsTer2) from his father was a frameshift mutation which had never been reported before and was identified as a pathogenic mutation based on the ACMG guideline. The boy was confirmed with CMD1A. A literature review of related articles in China and overseas revealed that most children with CMD1A have disease onset within 6 months after birth, with the features of motor developmental delay, elevated serum creatine kinase, and white matter impairment on imaging examination. The mutations of the LAMA2 gene have remarkable heterogeneity, the majority of which are null mutations. There are no specific treatment methods for CMD1A currently, and children with CMD1A usually have a poor long-term prognosis.

[DGUOK-related mitochondrial DNA depletion syndrome: a case report and literature review].

A boy, aged 4 months, had the major clinical manifestations of prolonged jaundice and hepatomegaly. Multiple biochemical tests revealed abnormal liver function along with elevated alpha-fetoprotein and lactate. Genetic analysis confirmed that the boy had the mutations of c.589C>T(p.Gln197Ter) and c.687G>C(p.Trp229Cys) in the DGUOK gene, both of which were novel mutations and were determined to be pathogenic and likely pathogenic respectively, by a variety of bioinformatics tools and the ACMG standard. Therefore, the boy was confirmed to have DGUOK-related mitochondrial DNA depletion syndrome. Literature review showed that onset of liver disease in infancy was the main clinical feature of this disease, and some children presented with nervous system manifestations. Abnormal laboratory results included abnormal liver function, increases in blood lactate, serum ferritin and alpha-fetoprotein, and hypoglycemia. Such children had marked heterogeneity of DGUOK gene mutations, with missense mutations as the most common type. This disease tended to have a poor prognosis, and 79.6% of the children died before the age of 3 years.

Intrahepatic Cholestasis of Pregnancy as a Clinical Manifestation of Sodium-Taurocholate Cotransporting Polypeptide Deficiency.

Intrahepatic cholestasis of pregnancy (ICP) is the most common pregnancy-related liver disorder. Although the etiology of ICP is not fully understood thus far, some genetic factors might contribute to the development of this condition. Sodium-taurocholate cotransporting polypeptide (NTCP), the protein encoded by the gene Solute Carrier Family 10, Member 1 (SLC10A1), is the primary transporter expressed in the basolateral membrane of the hepatocyte to uptake conjugated bile salts from the plasma. NTCP deficiency arises from biallelic SLC10A1 mutations which impair the NTCP function and cause intractably elevated levels of total bile acids (TBA) in the plasma (hypercholanemia). In this study, all the SLC10A1 exons and their flanking sequences were analyzed by Sanger sequencing to investigate the etiology for hypercholanemia in two male infants aged 2 and 20 months, respectively, from two unrelated families. As a result, both patients are homozygous for the reported pathogenic variant c.800C>T (p.Ser267Phe) that could impair the NTCP function to uptake bile acids, and the diagnosis of NTCP deficiency was thus made. Their mothers are also homozygotes of the same variant and both had been diagnosed to have ICP in the third trimester, with one of them undergoing cesarean section. The father of the first patient in this paper has the same SLC10A1 genotype c.800C>T/c.800C>T, also exhibiting slight hypercholanemia with a plasma TBA level of 21.5 µmol/L. In conclusion, we suggest that with hypercholanemia being a common laboratory change, NTCP deficiency may be a genetic factor leading to ICP and even cesarean section in clinical practice.

[Clinical features and ABCC2 genotypic analysis of an infant with Dubin-Johnson syndrome].

Dubin-Johnson syndrome (DJS) is an autosomal recessive disorder resulting from biallelic mutations of ABCC2 gene, with long-term or intermittent conjugated hyperbilirubinemia being the main clinical manifestation. This paper aims to report the clinical features and ABCC2 genotypes of an infant with DJS. A 9.5-month-old male infant was referred to the hospital due to abnormal liver function discovered over 9 months. The major clinical presentation was prolonged jaundice since neonatal period. A series of biochemistry analysis revealed markedly elevated total bilirubin, conjugated bilirubin and total bile acids. The patient had been managed in different hospitals, but the therapeutic effects were unsatisfactory due to undetermined etiology. Physical examination revealed jaundiced skin and sclera, and a palpable liver 3 cm below the right subcostal margin with medium texture. The spleen was not enlarged. Genetic analysis revealed a splice-site variant c.3988-2A>T and a nonsense variant c.3825C>G (p.Y1275X) in the ABCC2 gene of the infant, which were inherited from his mother and father respectively. The former had not been previously reported. Then ursodeoxycholic acid and phenobarbital were given orally. Half a month later, as a result, his jaundice disappeared and the biochemistry indices improved. However, the long-term outcome needs to be observed. Literature review revealed that neonates/infants with DJS presented with cholestatic jaundice soon after birth as the major clinical feature, and the ABCC2 variants exhibited marked heterogeneity.

[Identification and pathogenicity prediction of a novel GLB1 variant c.101T>C (p.Ile34Thr) in an infant with GM1 gangliosidosis].

GM1 gangliosidosis is an autosomal recessive disorder caused by galactosidase beta1 (GLB1) gene variants which affect the activity of ß-galactosidase (GLB). GLB dysfunction causes abnormalities in the degradation of GM1 and its accumulation in lysosome. This article reports the clinical and genetic features of a child with GM1 gangliosidosis. The girl, aged 2 years and 5 months, was referred to the hospital due to motor developmental regression for more than one year. Physical examination showed binocular deflection and horizontal nystagmus, but no abnormality was found on fundoscopy. The girl had increased muscular tone of the extremities, limitation of motion of the elbow, knee, and ankle joints, and hyperactive patellar tendon reflex. Blood biochemical examination showed a significant increase in aspartate aminotransferase. The 24-hour electroencephalographic monitoring detected frequent seizure attacks and diffuse θ wave activity, especially in the right hemisphere. Head magnetic resonance imaging showed thinner white matter in the periventricular region and diffuse high T2WI signal with unclear boundary. Three-dimensional reconstruction of white matter fiber tracts by diffusion tensor imaging showed smaller and thinner white matter fiber tracts, especially in the right hemisphere. Genetic analysis showed that the girl had compound heterozygous mutations of c.446C>T (p.Ser149Phe) and c.101T>C (p.Ile34Thr) in the GLB1 gene from her parents, among which c.101T>C (p.Ile34Thr) had not been reported in the literatures. The girl was finally diagnosed with GM1 gangliosidosis. Her conditions were not improved after antiepileptic treatment and rehabilitation training for 2 months.

[Clinical and genetic analysis of an infant with progressive familial intrahepatic cholestasis type II].

Progressive familial intrahepatic cholestasis type II (PFIC-2) is an autosomal recessive disorder caused by biallelic variants of ABCB11 gene. This paper reports the clinical and laboratory features of a pediatric patient with PFIC-2. The patient was a 2.4-month-old male infant with jaundice and hepatomegaly as the main clinical manifestations. The serum levels of total bilirubin, direct bilirubin and total bile acids were increased, while the serum γ-glutamyl transpeptidase (GGT) level was normal. Next generation sequencing revealed two missense variants, c.1493T>C(p.Ile498Thr) and c.1502T>G(p.Val501Gly), in the ABCB11 gene of the patient, which were inherited from his father and mother, respectively. The latter was a novel variant which was predicted to be pathogenic by using a variety of bioinformatic tools, and the affected p.Val501 residue was highly conserved in 112 homologous peptides.

[Clinical and genetic analysis of a pediatric patient with sodium taurocholate cotransporting polypeptide deficiency].

Sodium taurocholate cotransporting polypeptide (NTCP) deficiency is an inborn error of bile acid metabolism caused by mutations of SLC10A1 gene. This paper reports the clinical and genetic features of a patient with this disease. A 3.3-month-old male infant was referred to the hospital with the complaint of jaundiced skin and sclera over 3 months. Physical examination revealed moderate jaundice of the skin and sclera. The liver was palpable 3.5 cm below the right subcostal margin with a medium texture. Serum biochemistry analysis revealed markedly elevated bilirubin (predominantly direct bilirubin) and total bile acids (TBA), as well as decreased 25-OH-VitD level. On pathological analysis of the biopsied liver tissue, hepatocyte ballooning and cholestatic multinucleate giant cells were noted. The lobular architecture was distorted. Infiltration of inflammatory cells, predominantly lymphocytes, was seen in the portal tracts. In response to the anti-inflammatory and liver protective drugs as well as fat-soluble vitamins over 2 months, the bilirubin and transaminases levels were improved markedly while the TBA kept elevated. Because of persisting hypercholanemia on the follow-up, SLC10A1 gene analysis was performed at his age of 17.2 months. The child proved to be a homozygote of the reportedly pathogenic variant c.800C>T (p. Ser267Phe), while the parents were both carriers. NTCP deficiency was thus diagnosed. The infant was followed up until 34.3 months old. He developed well in terms of the anthropometric indices and neurobehavioral milestones. The jaundice disappeared completely. The liver size, texture and function indices all recovered. However, the hypercholanemia persisted, and the long-term outcome needs to be observed.

[Sodium taurocholate cotransporting polypeptide deficiency manifesting as cholestatic jaundice in early infancy: a complicated case study].

Sodium taurocholate cotransporting polypeptide (NTCP) deficiency is caused by SLC10A1 mutations impairing the NTCP function to uptake plasma bile salts into the hepatocyte. Thus far, patients with NTCP deficiency were rarely reported. The patient in this paper was a 5-month-19-day male infant with the complaint of jaundiced skin and sclera for 5.5 months as well as abnormal liver function revealed over 4 months. His jaundice was noticed on the second day after birth, and remained visible till his age of 1 month and 13 days, when a liver function test unveiled markedly elevated total, direct and indirect bilirubin as well as total bile acids (TBA). Cholestatic liver disease was thus diagnosed. Due to unsatisfactory response to medical treatment, the patient underwent exploratory laparotomy, cholecystostomy and cholangiography when aged 2 months. This revealed inspissated bile but unobstructed bile ducts. Thereafter, his jaundice subsided, but the aminotransferases and TBA levels gradually rose. Of note, his mother also had mildly elevated plasma TBA. Since the etiology was unclear, no specific medication was introduced. The infant has been followed up over 2 years. The aminotransferases recovered gradually, but TBA levels fluctuated within 23.3-277.7 µmol/L (reference range: 0-10 µmol/L). On SLC10A1 genetic analysis at 2 years and 9 months, both the infant and his mother proved to be homozygous for a pathogenic variant c.800C>T(p.S267F), and NTCP deficiency was thus definitely diagnosed. The findings suggest that, although only mildly increased plasma TBA is presented in adults with NTCP deficiency, pediatric patients with this disorder exhibit persistent and remarkable hypercholanemia, and some patients might manifest as cholestatic jaundice in early infancy.

[Clinical feature and genetic analysis of a family affected by congenital bile acid synthesis defect type 2: identification of 2 novel mutations in AKR1D1 gene].

Congenital bile acid synthesis defect type 2 (CBAS2) is an autosomal recessive disorder caused by biallelic mutations of AKR1D1 gene, which encodes the Δ4-3-oxo-steroid 5ß-reductase. Cholestatic jaundice is the main clinical manifestation, accompanied by malabsorption of fat and fat-soluble vitamins. This paper reported the clinical and genetic features of a CBAS2 patient definitely diagnosed by AKR1D1 genetic analysis. An 8-month-old male infant was referred to the hospital with the complaint of jaundiced skin and sclera over 7 months. On physical examination, growth retardation and malnutrition were discovered besides mild jaundice of the skin and sclera. The liver was palpable 8 cm below the right subcostal margin with medium texture, and the spleen was not enlarged. On liver function test, elevated levels of bilirubin (predominantly conjugated bilirubin) and transaminases were detected, but serum total bile acids and γ-glutamyl transpeptidase levels were within the normal ranges. Liver histopathologic analysis showed disorganized bile ducts, obvious multinucleated giant cells, significant cholestasis in hepatocytes, together with portal and interstitial fibrosis and lymphocytic infiltration. Via next generation sequencing analysis and Sanger sequencing confirmation, the infant proved to be a compound heterozygote of the AKR1D1 variants c.579+2delT and c.853C>T(p.Q285X), two novel mutations originated from his mother and father, respectively. CBAS2 was thus definitely diagnosed, and chenodeoxycholic acid was given orally. As a result, the abnormal liver function and hepatomegaly were improved gradually. On a follow-up 3 months later, a soft liver was palpable 2.5 cm below the right subcostal margin, and all liver function indices recovered to normal ranges.

[Clinical feature and molecular diagnostic analysis of the first non-caucasian child with infantile liver failure syndrome type 1].

Infantile liver failure syndrome type 1 (ILFS1) is a Mendelian disease due to biallelic mutations in the cytoplasmic leucyl-tRNA synthetase gene (LARS). This study aimed to report the clinical and molecular features of the first non-caucasian ILFS1 patient, providing reliable evidences for the definite diagnosis of ILFS1. The 2 years and 9 months old male patient was referred to the hospital with hepatosplenomegaly over 1 year. At age 17 months, he was found to have hepatosplenomegaly and anemia. Since then, he had been managed in different hospitals. The laboratory tests showed liver dysfunction, hypoproteinemia, coagulopathy and anemia, along with histologically-confirmed cirrhosis and fatty liver; however, the etiology remained undetermined. The subsequent SLC25A13 mutation analysis by means of prevalent mutation screening and Sanger sequencing only revealed a paternally-inherited mutation c.1658G>A, and no aberrant SLC25A13 transcripts could be detected from the maternal allele on cDNA cloning analysis, ruling out the possibility of citrin deficiency. Further target exome high-throughout sequencing of genes relevant to genetic liver diseases detected a paternal c.2133_2135del (p.L712del) and a maternal c.1183G>A (p.D395N) mutation in LARS gene. This finding was then confirmed by Sanger sequencing, and ILFS1 was thus definitely diagnosed. The child has been followed up till age 4 years, and his condition became stabilized.

[Clinical features and VPS33B mutations in a family affected by arthrogryposis, renal dysfunction, and cholestasis syndrome].

Arthrogryposis, renal dysfunction, and cholestasis (ARC) syndrome is an autosomal recessive disorder caused by mutations in the VPS33B or VIPAS39 gene. The aim of this study was to investigate the clinical features and VPS33B gene mutations of an infant with ARC syndrome. A 47-day-old female infant was referred to the hospital with the complaint of jaundiced skin and sclera for 45 days and abnormal liver function for 39 days. The patient had been managed in different hospitals, but the therapeutic effects were unsatisfactory due to undetermined diagnosis. Physical examination showed jaundice of the skin and sclera. Systemic skin was dry with desquamation in the limbs and trunk. There were no positive signs on cardiopulmonary examination. The liver was palpable 2.0 cm under the right subcostal margin. The hips and knees were flexed, and the extension was limited, with low muscular tone in the four limbs. Biochemical analysis demonstrated raised serum total bile acids, bilirubin (predominantly conjugated bilirubin) and transaminases, but the γ-glutamyl transpeptidase level was normal. Routine urine test revealed increased glucose as well as red and white blood cells. On genetic analysis, the infant was proved to be homologous for a VPS33B mutation c.1594C>T(p.R532X). She was definitely diagnosed to have ARC syndrome. Symptomatic and supportive therapy was given, but no improvement was observed, and the infant finally died at 3 months and 29 days of life.

[Clinical and genetic study of an infant with Alagille syndrome: identification of a novel chromosomal interstitial deletion including JAG1 gene].

Alagille syndrome (ALGS) is an autosomal dominant disease affecting multiple systems including the liver, heart, skeleton, eyes, kidneys and face. This paper reports the clinical and genetic features of an infant with this disease. A 3-month-and-10-day-old female infant was referred to the hospital with jaundiced skin and sclera for 3 months. Physical examination revealed wide forehead and micromandible. A systolic murmur of grade 3-4/6 was heard between the 2th and 3th intercostal spaces on the left side of the sternum. The abdomen was distended, and the liver palpable 3 cm under the right subcostal margin with a medium texture. Serum biochemistry analysis revealed abnormal liver function indices, with markedly elevated bilirubin (predominantly direct bilirubin), total bile acids (TBA) and gamma-glutamyl transpeptidase (GGT). Atrial septal defect and pulmonary stenosis were detected on echocardiography. Next generation sequencing detected entire deletion of the JAG1 gene, and then chromosomal microarray analysis revealed a novel interstitial deletion of 3.0 Mb in size on chr20p12.3p12.2, involving JAG1 gene. The child had special facial features, heart malformations, and cholestasis, and based on the genetic findings, ALGS was definitively diagnosed. Thereafter, symptomatic and supportive treatment was introduced. Thus far, the infant had been followed up till his age of 11 months. The hyperbilirubinemia got improved, but GGT and TBA were persistently elevated, and the long-term outcome needs to be observed. This study extended the JAG1 mutation spectrum, and provided laboratory evidences for the diagnosis and treatment of the patient, and for the genetic counseling and prenatal diagnosis in the family.

[Clinical features and MYO5B mutations of a family affected by microvillus inclusion disease].

Microvillus inclusion disease (MVID) is an autosomal recessive disorder caused by biallelic mutations in the MYO5B or STX3 gene. Refractory diarrhea and malabsorption are the main clinical manifestations. The aim of this study was to investigate the clinical features and MYO5B gene mutations of an infant with MVID. A 21-day-old female infant was referred to the hospital with the complaint of diarrhea for 20 days. On physical examination, growth retardation of the body weight and length was found along with moderately jaundiced skin and sclera. Breath sounds were clear in the two lungs and the heart sounds were normal. The abdomen was distended and the veins in the abdominal wall were observed. The liver and spleen were not palpable. Biochemical analysis revealed raised serum total bile acids, bilirubin, transaminases and γ-glutamyl transpeptidase while decreased levels of serum sodium, chloride, phosphate and magnesium. Blood gas analysis indicated metabolic acidosis. The preliminary diagnosis was congenital diarrhea, and thus parenteral nutrition was given along with other symptomatic and supportive measures. However, diarrhea, metabolic acidosis and electrolyte disturbance were intractable, and the cholestatic indices, including transaminases, γ-glutamyl transpeptidase, bilirubin and total bile acids, remained at increased levels. One month later, the patient was discharged and then lost contact. On genetic analysis, the infant was proved to be a compound heterozygote of the c.310+2Tdup and c.1966C>T(p.R656C) variants of the gene MYO5B, with c.310+2Tdup being a novel splice-site mutation. MVID was thus definitely diagnosed.

Mechanism for increased hepatic glycerol synthesis in the citrin/mitochondrial glycerol-3-phosphate dehydrogenase double-knockout mouse: Urine glycerol and glycerol 3-phosphate as potential diagnostic markers of human citrin deficiency.

The mitochondrial aspartate-glutamate carrier isoform 2 (citrin) and mitochondrial glycerol-3-phosphate dehydrogenase (mGPD) double-knockout mouse has been a useful model of human citrin deficiency. One of the most prominent findings has been markedly increased hepatic glycerol 3-phosphate (G3P) following oral administration of a sucrose solution. We aimed to investigate whether this change is detectable outside of the liver, and to explore the mechanism underlying the increased hepatic G3P in these mice. We measured G3P and its metabolite glycerol in plasma and urine of the mice under various conditions. Glycerol synthesis from fructose was also studied using the liver perfusion system. The citrin/mGPD double-knockout mice showed increased urine G3P and glycerol under normal, fed conditions. We also found increased plasma glycerol under fasted conditions, while oral administration of different carbohydrates or ethanol led to substantially increased plasma glycerol. Fructose infusion to the perfused liver of the double-knockout mice augmented hepatic glycerol synthesis, and was accompanied by a concomitant increase in the lactate/pyruvate (L/P) ratio. Co-infusion of either pyruvate or phenazine methosulfate, a cytosolic oxidant, with fructose corrected the high L/P ratio, leading to reduced glycerol synthesis. Overall, these findings suggest that hepatic glycerol synthesis is cytosolic NADH/NAD(+) ratio-dependent and reveal a likely regulatory mechanism for hepatic glycerol synthesis following a high carbohydrate load in citrin-deficient patients. Therefore, urine G3P and glycerol may represent potential diagnostic markers for human citrin deficiency.

Idiopathic eruptive macular pigmentation in a child with citrin deficiency.

Idiopathic eruptive macular pigmentation (IEMP) is a rare dermatological disorder with generally unclear etiology and pathogenesis. A 5½-year-old girl was referred to hospital with a 10 month history of brown skin rashes. In early infancy, citrin deficiency had been diagnosed with the SLC25A13 genotype c.851_854del4/c.998G > A, but all clinical and laboratory abnormalities recovered following the introduction of a lactose-free and medium-chain triglyceride-enriched formula. Physical examination at referral indicated symmetric, multiple and non-scaly brown macules on the neck, trunk, buttocks and proximal parts of the extremities. Histopathology indicated epidermal basal layer hyperpigmentation with an irregular distribution, along with a large number of melanophages in the upper dermis. The diagnosis of IEMP was thus made. Within 2 years of follow up, the rashes disappeared spontaneously and gradually. To our knowledge, this is the first description of IEMP in a patient with silent citrin deficiency.

[Clinical feature and ATP8B1 mutation analysis of a patient with progressive familial intrahepatic cholestasis type I].

Progressive familial intrahepatic cholestasis type I (PFIC1) is an autosomal recessive disorder caused by biallelic mutations of ATP8B1 gene, with progressive cholestasis as the main clinical manifestation. This paper reports the clinical and genetic features of a PFIC1 patient definitely diagnosed by ATP8B1 genetic analysis. The patient, a boy aged 14 months, was referred to the hospital with the complaint of jaundiced skin and sclera over 10 months. The patient had been managed in different hospitals, but the therapeutic effects were unsatisfactory due to undetermined etiology. On physical examination, hepatosplenomegaly was discovered in addition to jaundice of the skin and sclera. The liver was palpable 4 cm below the right subcostal margin and 2 cm below the xiphoid while the spleen 2 cm below the left subcostal margin. The liver function test revealed elevated levels of serum total bile acids, bilirubin, and transaminases; however, the γ-glutamyl transferase level was normal. The diagnosis was genetic cholestasis of undetermined origin. At the age of 1 year and 8 months, a Roux-en-Y cholecystocolonic bypass operation was performed, and thereafter the jaundice disappeared. At 5 years and 1 month, via whole genome sequencing analysis and Sanger sequencing confirmation, the boy was found to be a homozygote of mutation c.2081T>A(p.I694N) of ATP8B1 gene, and thus PFIC1 was definitely diagnosed. The boy was followed up until he was 6 years, and jaundice did not recur, but the long-term outcome remains to be observed.

[Clinical features and DGUOK mutations of an infant with mitochondrial DNA depletion syndrome].

The aim of this study was to investigate the clinical features and DGUOK gene mutations of an infant with mitochondrial DNA depletion syndrome (MDS). The patient (more than 7 months old) manifested as hepatosplenomegaly, abnormal liver function, nystagmus and psychomotor retardation. Genetic DNA was extracted from peripheral blood samples of the patient and her parents. Targeted Exome Sequencing was performed to explore the genetic causes. Sanger sequencing was carried out to confirm the detected mutations. The sequencing results showed that the patient was a compound heterozygote for c.679G>A and c.817delT in the DGUOK gene. The former was a reportedly pathogenic missense mutation of maternal origin, while the latter, a frameshift mutation from the father, has not been described yet. The findings in this study expand the mutation spectrum of DGUOK gene, and provide molecular evidence for the etiologic diagnosis of the patient as well as for the genetic counseling and prenatal diagnosis in the family.

[Identification of a novel JAG1 mutation in a family affected by Alagille syndrome].

Alagille syndrome (ALGS) is an autosomal dominant disorder which is mainly caused by JAG1 gene mutation and can affect multiple systems including the liver, heart, eyes, skeleton and face. This paper reports the clinical and genetic features of an ALGS patient. A 2-year-and-9-month-old boy was referred to the hospital with the complaint of abnormal liver function and heart murmur discovered over two years. Jaundice of the skin and sclera was not observed. The child had a prominent forehead, left esotropia, depressed nasal bridge and micromandible. The two lungs were clear on auscultation, but a systolic cardiac murmur of grade 2/6 could be heard between the 2nd and 3rd intercostal space at the left sternal border. Neither abdominal distension nor enlarged liver or spleen was discovered. X-ray radiography uncovered butterfly malformation of the 6th and 8th thoracic vertebrae. Serum biochemistry analysis revealed elevation of total bile acids, bilirubin and transaminases. Based on the clinical characteristics and the consultation opinion of the ophthalmologist, the child was diagnosed to have ALGS with Duane retraction syndrome. DNA direct sequencing detected a novel JAG1 mutation c.2419delG(p.Glu807AsnfsX819) in the child. Symptomatic and supportive therapy was performed thereafter and clinical follow-up was conducted until he was 4 years and 2 months. In the follow-up visits, his general condition remained stable, but the facial malformations, left esotropia, cardiac murmur and abnormal liver function persistend. The long-term outcome needed to be observed.