Pathogenic Potential of a PCK1 Gene Variant in Cytosolic PEPCK Deficiency: A Compelling Case Study

BACKGROUND Cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) deficiency is an extremely rare autosomal recessive inherited error of metabolism in which gluconeogenesis is impaired, resulting in life-threatening episodes of hypoglycemia and metabolic acidosis. The diagnosis of gluconeogenesis disorders is challenging. In the diagnostic pathway, the molecular test plays a paramount role. CASE REPORT The aim of the paper is to present the case report of a girl with recurrent episodes of severe hypoglycemia, in whom molecular diagnosis enabled the confirmation of PEPCK - C deficiency. The patient experienced 4 episodes of severe hypoglycemia. Most of them were accompanied by hyperlacticaemia, metabolic acidosis, and elevated liver enzymes. All of the metabolic decompensations were triggered by infectious agents. The episodes resolved after continuous infusion of high-dose glucose. Due to the recurrent character of the disease, a genetic condition was suspected. The differential diagnosis included metabolic and endocrinological causes of hypoglycemia. Two variants in the PCK1 gene were detected: c.265G>A p.(Glu89Lys) in exon 3 and c.925G>A p.(Gly309Arg) in exon 6. As c.925G>A p.(Gly309Arg) is a known pathogenic variant, the second variant was first described in June 2023 in the ClinVar database and described as "with unknown clinical significance". CONCLUSIONS According to the clinical symptoms observed in the presented case, the variant c.265G>A p.(Glu89Lys) in PCK1 gene should be considered likely pathogenic. We suggest considering molecular diagnostics in every patient presented with recurrent, severe hypoglycemia with accompanying liver damage as most accurate, feasible, and reliable method.

Neutrophil functions in patients with neutropenia due to glycogen storage disease type 1b treated with empagliflozin

Neutropenia and neutrophil dysfunction in glycogen storage disease type 1b (GSD1b) are caused by the accumulation of 1,5-anhydroglucitol-6-phosphate (1,5-AG6P) in granulocytes. The antidiabetic drug empagliflozin reduces the concentration of 1,5-anhydroglucitol (1,5 AG), thus restoring neutrophil counts and functions, leading to promising results in previous case reports. Here, we present a comprehensive analysis of neutrophil function in seven GSD1b patients and 11 healthy donors, aiming to evaluate the immediate (after 3 months) and long-term (after 12 months) efficacy of empagliflozin compared to the reference treatment with granulocyte-colony stimulating factor (G-CSF). We found that most patients receiving G-CSF remained neutropenic with dysfunctional granulocytes, whereas treatment with empagliflozin increased neutrophil counts and improved functionality by inhibiting apoptosis, restoring phagocytosis and the chemotactic response, normalizing the oxidative burst, and stabilizing cellular and plasma levels of defensins and lactotransferrin. These improvements correlated with the decrease in serum 1,5-AG levels. However, neither G-CSF nor empagliflozin overcame deficiencies in the production of cathelicidin/LL-37 and neutrophil extracellular traps. Given the general improvement promoted by empagliflozin treatment, patients were less susceptible to severe infections. G-CSF injections were therefore discontinued in six patients (and the dose was reduced in the seventh) without adverse effects. Our systematic analysis, the most extensive reported thus far, has demonstrated the superior efficacy of empagliflozin compared to G-CSF, restoring the neutrophil population and normal immune functions. EudraCT 2021-000580-78.

Preservative-free Bimatoprost 0.01% Ophthalmic Gel for Glaucoma Therapy. A Phase III Randomized Controlled Trial

PURPOSE

To evaluate the intraocular pressure (IOP)-lowering efficacy and safety of a preservative-free bimatoprost 0.01% ophthalmic gel (PFB 0.01% gel) compared with preserved bimatoprost 0.01% (PB 0.01%).

DESIGN

Phase III, international, multicenter, randomized, 2-parallel group, investigator-masked, 3-month treatment duration.

METHODS

Patients with glaucoma or ocular hypertension were randomized after a 7 week run-in/washout period to receive once-daily PFB 0.01% gel (n=236) or PB 0.01% (n=249) for 3 months. The primary efficacy measure was change from baseline in IOP at Week 12. Safety measures included adverse events (AEs) and assessment of conjunctival hyperemia.

RESULTS

Mean change from baseline in IOP at Week 12 in the PFB 0.01% gel and PB 0.01% were -9.72±2.97 mmHg and -9.47±3.06, respectively at 8 am, -9.41±3.03 and -9.19±3.12 mmHg at 10 am, and -8.99±3.36 and -8.54±3.44 mmHg at 4 pm. Noninferiority of PFB 0.01% gel to PB 0.01% was demonstrated at Week 12 based on predetermined criteria (upper 95% confidence interval margin of 1.5 mmHg at all timepoints). The most frequently reported AE was conjunctival hyperemia; 13 (5.5%) patients with PFB 0.01% gel and 17 (6.8%) patients with PB 0.01%. The percentage of patients experiencing a worsening from baseline in conjunctival hyperemia score was lower with PFB 0.01% gel compared to PB 0.01% at Week 6 (20.1% vs 29.3%, respectively) and Week 12 (18.3% vs 30.4%, respectively).

CONCLUSIONS

PFB 0.01% ophthalmic gel has the same efficacy in lowering IOP as PB 0.01% and demonstrated less aggravation of conjunctival hyperemia at Week 6 and Week 12.

Metabolic encephalopathies in children: A pragmatic diagnostic approach based on literature analysis

Inborn errors of metabolism (IEM) in the general population are rare diseases. However, from the perspective of general pediatrics and pediatric intensive care units (PICUs), they are becoming a significant challenge both diagnostically and therapeutically. Clinically, there is a useful division of IEMs with neurological manifestations into 2 categories: acute and progressive encephalopathies. The extent of individual IEMs in these 2 groups varies, requiring different diagnostic strategies. Despite progress in development of diagnostic tools in IEM, initial diagnosis is made on the basis of basic laboratory tests, neuroradiological findings and metabolic screening. In settings of shortage of diagnostic resources and under time pressure, rational decisions should be made based on available clinical data. The text discusses diagnostic aspects of IEM presenting as metabolic encephalopathies, highlighting their significance in the context of general pediatric care and intensive care units (ICUs), and the challenges associated with diagnosis. It should be noted that the paper does not include a discussion of epileptic encephalopathies of IEM etiology, although some cases of metabolic encephalopathies may also present initially as epileptic encephalopathy.

Relationship between Bone Mineral Density and Selected Parameters of Calcium-Phosphate Economy with Dietary Management and Metabolic Control in Polish Pediatric Patients with Classical Homocystinuria-A Preliminary Study

BACKGROUND

Classical homocystinuria (HCU) is an inborn defect of methionine metabolism caused by a deficiency of the enzyme cystathionine β-synthase (CBS). The main symptoms of classical homocystinuria are lens subluxation, bone lesions, vascular disease and developmental delay/intellectual disability. The treatment method for HCU is a methionine-poor diet supplemented with amino acid preparations. The aim of the study was to examine the relationship of dietary factors, metabolic compensation and selected skeletal parameters in patients with HCU.

METHODS

Bone mineral density measurements (DXA) were performed in pediatric patients with HCU, and blood levels of selected amino acids, minerals and vitamins, as well as dietary nutritional value, were analyzed.

RESULTS

A total of 11 patients with HCU whose median age was 9.3 years were enrolled in the study. The median DXA total body less head of HCU patients was -0.4 z-score, and the lumbar spine was -1.4 z-score. Despite supplementation, calcium intake was below the age norm. Average vitamin D3 intake was in line with recommendations, but 36% of patients had reduced blood levels. Bone mineral density depended on blood levels of 25-hydroxyvitamin D, homocysteine and methionine, as well as on BMI, age and intake of natural protein (R2 = 98.5%, p = 0.015; R2 = 86.7%, p = 0.0049) and protein from an amino acid preparation (r = 0.69, p = 0.026).

CONCLUSION

The results of the study indicate the need for regular densitometry in patients with HCU and also the use of additional calcium and vitamin D3 supplementation. It is also necessary to perform a comprehensive analysis of the diet and metabolic controls.

S100B Protein but Not 3-Nitrotyrosine Positively Correlates with Plasma Ammonia in Patients with Inherited Hyperammonemias: A New Promising Diagnostic Tool?

Individuals with inherited hyperammonemias often present developmental and intellectual deficiencies which are likely to be exaggerated by hyperammonemia episodes in long-term outcomes. In order to find a new, systemic marker common to the course of congenital hyperammonemias, we decided to measure the plasma level of S100 calcium-binding protein B (S100B), which is associated with cerebral impairment. Further, we analyzed three mechanistically diverged but linked with oxidative-nitrosative stress biochemical parameters: 3-nitrotyrosine (3-NT), a measure of plasma proteins' nitration; advanced oxidation protein products (AOPP), a measure of protein oxidation; and glutathione peroxidase (GPx) activity, a measure of anti-oxidative enzymatic capacity. The plasma biomarkers listed above were determined for the first time in congenital hyperammonemia. Also, the level of pro- and anti-inflammatory mediators (i.e., IL-12, IL-6, IL-8, TNF-α, IL-1β, and IL-10) and chemokines (IP-10, MCP-1, MIG, and RANTES) were quantified. S100B was positively correlated with plasma ammonia level, while noticeable levels of circulating 3-NT in some of the patients' plasma did not correlate with ammonia concentration. Overall, the linear correlation between ammonia and S100B but not standard oxidative stress-related markers offers a unique perspective for the future identification and monitoring of neurological deficits risk-linked with hyperammonemia episodes in patients with inherited hyperammonemias. The S100B measure may support the development of therapeutic targets and clinical monitoring in these disorders.

Perinatal manifestations of congenital disorders of glycosylation-A clue to early diagnosis

N-glycosylation defects-isolated or mixed with other glycosylation defects-are the most frequent congenital disorders of glycosylation and present mostly in childhood, with a specific combination of non-specific phenotypic features. The diagnosis, however, is often delayed. The aim of this study is to describe the perinatal phenotype of congenital disorders of N-glycosylation. We present an analysis of perinatal symptoms in a group of 24 one-center Polish patients with N-glycosylation defects-isolated or mixed. The paper expands the perinatal phenotype of CDGs and shows that some distinctive combinations of symptoms present in the perinatal period should raise a suspicion of CDGs in a differential diagnosis.

Sodium‐glucose cotransporter type 2 channel inhibitor: Breakthrough in the treatment of neutropenia in patients with glycogen storage disease type 1b?

Glycogen storage disease type 1b (GSD 1b) is an inherited metabolic defect caused by biallelic mutations in the SLC37A4 gene encoding microsomal glucose‐6‐phosphate (G6P) transporter in the endoplasmic reticulum (ER) membrane. Ineffective G6P transport into the ER leads to hypoglycaemia, hyperlactatemia, hyperuricemia, hypertriglyceridemia, hepato‐ and/or nephromegaly. Clinical manifestations of the disease include recurrent, severe infections and inflammatory bowel (Crohn‐like) caused by neutropenia and diminished bactericidal and fungicidal activity of neutrophils. Granulocyte colony‐stimulating factor (G‐CSF) administration is currently a standard therapy to prevent adverse effects of neutropenia, but the treatment is associated with a high risk of severe side effects. On the other hand, short‐treatment with sodium‐glucose cotransporter type 2 inhibitor – empagliflozin (EMPA) was reported to act directly on the mechanism of neutropenia and neutrophil dysfunction in GSD 1b. We observed significant improvement in clinical and laboratory parameters after introducing EMPA to treatment, that is reduced frequency of infections, lower number of bowel movements, and improved postoperative wound healing. EMPA is effective in the treatment of neutropenia in our GSD 1b patients, which allows for dose reduction and even withdrawal of G‐CSF. We did not observe any significant side effects of EMPA treatment in our patients.

Clinical characteristics and long-term outcomes of patients with glycogen storage disease type 1b: a retrospective multi-center experience in Poland

Glycogen storage disease type 1b (GSD 1b) is an inherited metabolic defect caused by a deficiency of microsomal glucose-6-phosphate (G6P) transport protein across the endoplasmic reticulum membrane. Patients with GSD 1b have hypoglycemia episodes, lactate acidosis, hypertriglyceridemia, hypercholesterolemia, hyperuricemia, neutropenia and in imaging studies hepatomegaly and/or nephromegaly. The primary goals of treatment are to maintain proper blood glucose levels and to increase the number of properly functioning neutrophils. The aim of the study was a retrospective analysis of the clinical picture and treatment results of pediatric patients with type 1b glycogen storage disease from Poland. The study included 13 patients from 3 clinical centers, with a median age at diagnosis as 5 months. In 11/13 patients, the diagnosis was confirmed by molecular test, by the presence of pathogenic variants on both alleles of the SLC37A4 gene. Ten out of 13 patients developed the first symptoms in the form of severe infection (sepsis and/or pneumonia) already in the neonatal-infant period. A hypoglycemia episode was observed before diagnosis in 8/13 patients, of which 4/8 patients presented symptoms in the form of generalized relaxation and/or seizures. Two patients developed hypertension, and 4/13 required long-term treatment of inflammatory bowel disease.

The fibroblast growth factor 21 concentration in children with mitochondrial disease does not depend on the disease stage, but rather on the disease genotype

ABSTRACT

The fibroblast growth factor 21 (FGF21) is a new biomarker of mitochondrial diseases (MD). FGF21 concentration may be used to define the severity of mitochondrial disease.

AIM OF THE STUDY

The study objective was to verify if the FGF21 concentration in paediatric patients with MD was correlated with the disease severity and stage and to assess the correlation between FGF21 levels and the genetic background of MD.

MATERIAL AND METHODS

The disease stage in MD subjects was determined on the basis of the International Paediatric Mitochondrial Disease Scale (IPMDS) and the concentrations of FGF21, lactic and pyruvic acids, alanine and creatine kinase in serum were assessed in those patients.

RESULTS

The median age of children with MD (n = 32) was 33 months (range: 2-213), in the control group (n = 21) the median age was 42 months (range: 8-202). The concentrations of FGF21, lactic acid and pyruvic acid were higher in MD patients than in the control group. No correlation between the disease severity (IPMDS) and serum FGF21 concentration was found. The FGF21 concentration was higher in patients whose MD resulted from nuclear gene damage (nDNA), median FGF21 = 1022 (84-8873) pg/ml, than in patients with MD resulting from mitochondrial damage (mtDNA), median FGF21 = 736 (188-2906) pg/ml, or with an abnormal variant in the PDHA1 gene, median FGF21 = 58 (25-637) pg/ml.

CONCLUSIONS

There is no correlation between the stage of MD and FGF21 level. Higher FGF21 values are seen in patients whose MD results from an abnormal nDNA variant rather than mtDNA damage.

Sensorineural hearing loss in GSD type I patients. A newly recognized symptomatic association of potential clinical significance and unclear pathomechanism

OBJECTIVE

Glycogen storage disease (GSD) type I is an inborn error of carbohydrates metabolism characterized by inability to convert glucose-6-phosphate to glucose. It presents with serious liver and metabolic complications, as well as in type Ib with severe infections due to neutropenia. So far, the sensorineural hearing impairment has not been reported in these patients. Bilateral, sensorineural hearing impairment was diagnosed in four unrelated GSDI patients. Congenital origin of hearing loss and descending audiometric curves warranted the need for future investigations.

METHODS

Hearing status was assessed in entire group of 40 children with GSD type I. Then, molecular testing, massive parallel sequencing was performed in the four probands and their parents in order to find possible genetic background of auditory dysfunction in these patients.

RESULTS

Pathogenic variants in G6PC and SLC37A4 related to the phenotypes of GSDI subtype Ia and subtype Ib were detected, each in two probands, respectively. No change in the genes involved in auditory pathway dysfunction was found.

CONCLUSIONS

Sensorineural hearing loss appears to be associated with GSDI in approximately one out of ten cases. Careful assessment and monitoring of auditory functions of patients with GSDI is recommended.

Psychiatric Symptoms as the First or Solitary Manifestation of Somatic Illnesses: Hyperammonaemia Type II

AIM

We describe the difficulties encountered in making a diagnosis where a somatic condition manifests itself alongside psychiatric symptoms associated with possible psychiatric comorbidities.

METHODS

A case study is presented of a 15-year-old girl who was eventually diagnosed with ornithine transcarbamylase (OTC) deficiency (hyperammonaemia type II), following an initial diagnosis of pervasive developmental disorder, selective mutism, and anorexia nervosa.

RESULTS

The OTC disease is not fully expressed in females and its prevalence is lower than in males. Around 17-20% of female patients found with a defective OTC gene on an X chromosome can suffer from OTC deficiency that may result in elevated levels of ammonia in the blood; this occurs when one of the X chromosomes become inactivated. Patients typically present with nausea, migraines, and a history of dietary protein avoidance. In more severe cases, ataxia, confusion, hallucinations, and cerebral oedema can occur. The OTC deficiency can thus remain undiagnosed in women for many years.

CONCLUSION

Somatic comorbidity in psychiatric inpatients is commonly found; however, such disorders are rarely diagnosed or even treated adequately.

COVID-19 Pandemic and Patients with Rare Inherited Metabolic Disorders and Rare Autoinflammatory Diseases-Organizational Challenges from the Point of View of Healthcare Providers

COVID-19 pandemic is an organisational challenge for both healthcare providers and patients. People with rare inherited metabolic disorders (IMD) and rare autoinflammatory diseases (AD) are vulnerable patients whose well-being is deeply connected with regular follow-ups. This study aimed to assess how e one year of coronavirus pandemic has impacted the treatment of patients with IMD and AD in Poland. Surveys were distributed to all healthcare providers that coordinate the treatment of IMD and AD patients. Thirty-two responders (55%) answered the survey. They provide care to 1726 patients with IMD/AD, including 246 patients on dedicated treatment. In 35% of units, the regular appointments were disrupted, primarily because of patient infection. In 18 hospitals, remote visits were implemented, but only 66.6% of patients used this form of consultation. In 14/32 hospitals, administration of the therapy was delayed (median: 17.4 days). Forty-four patients suffered from SARS-COV-2 infection, in majority with mild symptoms. However, four adult patients developed complications, and one died following a SARS-COV-2 infection. Although most hospitals managed to maintain regular visits during the pandemic, more comprehensive implementation of telemedicine and switch to oral therapy or home infusions would be a reasonable solution for the current epidemic situation.

Early treatment of biotin-thiamine-responsive basal ganglia disease improves the prognosis

Background

Biotin–thiamine–responsive basal ganglia disease (BTBGD) is an autosomal recessive neurometabolic disorder associated with pathogenic variants in SLC19A3 gene. The clinical picture includes symptoms of subacute encephalopathy (e.g. confusion, dysphagia, dysarthria, and seizures), which respond very well to early treatment with thiamine and biotin.

Method

A retrospective review of clinical characteristics, magnetic resonance imaging and molecular findings in 3 patients with BTBGD.

Results

The first symptoms in all patients occurred at 12–24 months of age and they had subacute encephalopathy, ataxia and dystonia. The baseline magnetic resonance imaging demonstrated abnormal signal intensity in the basal ganglia with atrophy and necrosis of the basal ganglia during follow-up in two patients. One patient was diagnosed and the treatment was initiated after a long period from symptoms onset and he is currently severely affected, with dystonia, quadriparesis and seizures. The other two patients were diagnosed early in life and are currently stable on treatment, without the clinical symptoms. Genetic testing demonstrated pathogenic variants in SLC19A3 gene.

Conclusion

To avoid diagnostic errors and delayed or incorrect treatment, BTBGD must be recognized early. Adequate prompt treatment gives the chance of significant clinical improvement. Unexplained encephalopathy and MRI abnormalities including bilateral abnormal signal in the basal ganglia should alert the clinician to consider BTBGD in the differential, and the treatment with biotin and thiamine should be introduced immediately.

NBAS deficiency due to biallelic c.2809C > G variant presenting with recurrent acute liver failure with severe hyperammonemia, acquired microcephaly and progressive brain atrophy

Biallelic pathogenic variants in the neuroblastoma amplified sequence (NBAS) gene were firstly (2015) identified as a cause of fever-triggered recurrent acute liver failure (RALF). Since then, some patients with NBAS deficiency presenting with neurologic features, including a motor delay, intellectual disability, muscular hypotonia and a mild brain atrophy, have been reported. Here, we describe a case of pediatric patient diagnosed with NBAS deficiency due to a homozygous c.2809C > G, p.(Pro937Ala) variant presenting with RALF with severe hyperammonemia, acquired microcephaly and progressive brain atrophy. Not reported in the literature findings include severe hyperammonemia during ALF episode, and neurologic features in the form of acquired progressive microcephaly with brain atrophy. The latter raises the hypothesis about a primary neurologic phenotype in NBAS deficiency.

Noncoding sequence variants define a novel regulatory element in the first intron of the N-acetylglutamate synthase gene

N-acetylglutamate synthase deficiency is an autosomal recessive urea cycle disorder caused either by decreased expression of the NAGS gene or defective NAGS enzyme resulting in decreased production of N-acetylglutamate (NAG), an allosteric activator of carbamylphosphate synthetase 1 (CPS1). NAGSD is the only urea cycle disorder that can be effectively treated with a single drug, N-carbamylglutamate (NCG), a stable NAG analog, which activates CPS1 to restore ureagenesis. We describe three patients with NAGSD due to four novel noncoding sequence variants in the NAGS regulatory regions. All three patients had hyperammonemia that resolved upon treatment with NCG. Sequence variants NM_153006.2:c.427-222G>A and NM_153006.2:c.427-218A>C reside in the 547 bp-long first intron of NAGS and define a novel NAGS regulatory element that binds retinoic X receptor α. Sequence variants NC_000017.10:g.42078967A>T (NM_153006.2:c.-3065A>T) and NC_000017.10:g.42078934C>T (NM_153006.2:c.-3098C>T) reside in the NAGS enhancer, within known HNF1 and predicted glucocorticoid receptor binding sites, respectively. Reporter gene assays in HepG2 and HuH-7 cells demonstrated that all four substitutions could result in reduced expression of NAGS. These findings show that analyzing noncoding regions of NAGS and other urea cycle genes can reveal molecular causes of disease and identify novel regulators of ureagenesis.

The potential of dietary treatment in patients with glycogen storage disease type IV

There is paucity of literature on dietary treatment in glycogen storage disease (GSD) type IV and formal guidelines are not available. Traditionally, liver transplantation was considered the only treatment option for GSD IV. In light of the success of dietary treatment for the other hepatic forms of GSD, we have initiated this observational study to assess the outcomes of medical diets, which limit the accumulation of glycogen. Clinical, dietary, laboratory, and imaging data for 15 GSD IV patients from three centres are presented. Medical diets may have the potential to delay or prevent liver transplantation, improve growth and normalize serum aminotransferases. Individual care plans aim to avoid both hyperglycaemia, hypoglycaemia and/or hyperketosis, to minimize glycogen accumulation and catabolism, respectively. Multidisciplinary monitoring includes balancing between traditional markers of metabolic control (ie, growth, liver size, serum aminotransferases, glucose homeostasis, lactate, and ketones), liver function (ie, synthesis, bile flow and detoxification of protein), and symptoms and signs of portal hypertension.

Clinical, biochemical and molecular phenotype of congenital disorders of glycosylation: long-term follow-up

Background

Congenital disorders of glycosylation (CDG) result from defects in the synthesis of glycans and the attachment of glycans to proteins and lipids. Our study aimed to describe the clinical, biochemical, and molecular findings of CDG patients, and to present the long-term follow-up.

Material and methods

A single-center study (1995–2019 years) of patients with congenital disorders of N-glycosylation and combined N- and O-hypoglycosylation was performed.

Results

Among 32 patients included into the study, there were 12 PMM2-CDG, 3 ALG13-CDG, 3 ALG1-CDG, 1 ALG3-CDG, 3 MPI-CDG, 1 PGM1-CDG, 4 SRD5A3-CDG, 1 DPAGT1-CDG, 3 ATP6AP1-CDG, 1 ATP6V0A2-CDG. The phenotypic and genotypic spectrum during long-term (in some cases over 20 years) observation was characterised and several measurements of serum Tf isoforms taken. Statistical analysis revealed strong negative correlation between asialo-Tf and tetrasialo-Tf, as well as between disialo-Tf and tetrasialo-Tf. Within CDG type I, no difference in % Tf isoforms was revealed between PMM2-CDG and non-PMM2-CDG patients. However, these two groups differed significantly in such diagnostic features as: cerebellar ataxia, failure to thrive, hypothyroidism, pericardial effusion, cardiomyopathy, inverted nipples, prolonged INR.

The effect of treatment with mannose in 2 patients with MPI-CDG was assessed and we found that % of asialo-Tf, monosialo-Tf, and disialo-Tf was significantly lowered, whereas tetrasialo-Tf and pentasialo-Tf rose, coming closer or falling into the reference range.

Conclusions

The novel finding was an abnormal Tf IEF pattern in two ALG13-CDG patients and normal in one ALG1-CDG patient. Clinical manifestation of presented CDG patients was similar to that reported in the literature. Mannose supplementation in MPI-CDG patients, as well as galactose supplementation in PGM1-CDG patient, improved patients’ clinical picture and Tf isoform profiles.

Hepatic glycogen storage diseases: pathogenesis, clinical symptoms and therapeutic management

Glycogen storage diseases (GSDs) are genetically determined metabolic diseases that cause disorders of glycogen metabolism in the body. Due to the enzymatic defect at some stage of glycogenolysis/glycogenesis, excess glycogen or its pathologic forms are stored in the body tissues. The first symptoms of the disease usually appear during the first months of life and are thus the domain of pediatricians. Due to the fairly wide access of the authors to unpublished materials and research, as well as direct contact with the GSD patients, the article addresses the problem of actual diagnostic procedures for patients with the suspected diseases. Knowledge and awareness of the problem among physicians seem insufficient, and research on the diagnosis and treatment of GSD is still ongoing, resulting in a heterogeneous GSD typology and a changing way of its diagnosis and treatment.

Neonatal cholestasis due to citrin deficiency: diagnostic pitfalls

Citrin deficiency can manifest in newborns or infants as neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD). The paper presents a case of Polish NICCD patient presenting with low birth weight, failure to thrive, prolonged cholestatic jaundice with coagulopathy and hypoalbuminemia with normal results of MS/MS newborn screening but with high blood citrulline level observed at 3 months of age. Unreported findings included N-hypoglycosylation and increased serum very-long-chain fatty acids (VLCFA), probably secondary to liver impairment. Final diagnosis was established based on whole-exome sequencing (WES) analysis.

ATP6AP1-CDG: Follow-up and female phenotype

In 2016, 11 male patients were reported with immunodeficiency and hepatic, gastric and (in some) neurological disease due to X-linked ATP6AP1 deficiency (ATP6AP1-CDG). In 2018, three other patients were reported with additional features: connective tissue abnormalities, sensorineural hearing loss, hyperopia, glomerular and tubular dysfunction, exocrine pancreatic insufficiency and altered amino acid and lipid metabolism. We here present a follow-up of three reported siblings showing progression of deafness to total hearing loss, progressive loss of hair up to alopecia, chestnut skin and, at last follow-up, in some of them proteinuria. Three female carriers showed a normal serum transferrin isoelectrofocusing but in two of them there was a persistent proteinuria.

Mild phenotype of glutaric aciduria type 1 in polish patients - novel data from a group of 13 cases

Glutaric aciduria type 1 is a neurometabolic disorder, caused by riboflavin-dependent glutaryl-CoA dehydrogenase deficiency. As its consequence, accumulation of the putatively neurotoxic metabolites (glutaric and 3-hydroxyglutaric acids) in body tissues, but especially within the brain, is observed. Estimated incidence of the disease is 1 in 110,000 newborns, The prevalence however may be higher, depending on a specific ethnic group, and result in phenotypic variation as well. In this paper we present clinical data of 13 patients of Polish nationality. They all present a mild phenotype and clinical course of glutaric aciduria type 1. Based on their clinical data, presented herein, we like to pay attention to the phenotypic and neuroimaging features important for the diagnosis of mild form of this disease. Moreover, we present novel molecular data, which may correlate with such a manifestation.

Leigh syndrome caused by mutations in MTFMT is associated with a better prognosis

Objectives

Mitochondrial methionyl‐tRNA formyltransferase (MTFMT) is required for the initiation of translation and elongation of mitochondrial protein synthesis. Pathogenic variants in MTFMT have been associated with Leigh syndrome (LS) and mitochondrial multiple respiratory chain deficiencies. We sought to elucidate the spectrum of clinical, neuroradiological and molecular genetic findings of patients with bi‐allelic pathogenic variants in MTFMT.

Methods

Retrospective cohort study combining new cases and previously published cases.

Results

Thirty‐eight patients with pathogenic variants in MTFMT were identified, including eight new cases. The median age of presentation was 14 months (range: birth to 17 years, interquartile range [IQR] 4.5 years), with developmental delay and motor symptoms being the most frequent initial manifestation. Twenty‐nine percent of the patients survived into adulthood. MRI headings in MTFMT pathogenic variants included symmetrical basal ganglia changes (62%), periventricular and subcortical white matter abnormalities (55%), and brainstem lesions (48%). Isolated complex I and combined respiratory chain deficiencies were identified in 31% and 59% of the cases, respectively. Reduction of the mitochondrial complex I and complex IV subunits was identified in the fibroblasts (13/13). Sixteen pathogenic variants were identified, of which c.626C>T was the most common. Seventy‐four percent of the patients were alive at their last clinical review (median 6.8 years, range: 14 months to 31 years, IQR 14.5 years).

Interpretation

Patients that harbour pathogenic variants in MTFMT have a milder clinical phenotype and disease progression compared to LS caused by other nuclear defects. Fibroblasts may preclude the need for muscle biopsy, to prove causality of any novel variant.

Clinical, biochemical and genetic spectrum of 70 patients with ACAD9 deficiency: is riboflavin supplementation effective?

BACKGROUND

Mitochondrial acyl-CoA dehydrogenase family member 9 (ACAD9) is essential for the assembly of mitochondrial respiratory chain complex I. Disease causing biallelic variants in ACAD9 have been reported in individuals presenting with lactic acidosis and cardiomyopathy.

RESULTS

We describe the genetic, clinical and biochemical findings in a cohort of 70 patients, of whom 29 previously unpublished. We found 34 known and 18 previously unreported variants in ACAD9. No patients harbored biallelic loss of function mutations, indicating that this combination is unlikely to be compatible with life. Causal pathogenic variants were distributed throughout the entire gene, and there was no obvious genotype-phenotype correlation. Most of the patients presented in the first year of life. For this subgroup the survival was poor (50% not surviving the first 2 years) comparing to patients with a later presentation (more than 90% surviving 10 years). The most common clinical findings were cardiomyopathy (85%), muscular weakness (75%) and exercise intolerance (72%). Interestingly, severe intellectual deficits were only reported in one patient and severe developmental delays in four patients. More than 70% of the patients were able to perform the same activities of daily living when compared to peers.

CONCLUSIONS

Our data show that riboflavin treatment improves complex I activity in the majority of patient-derived fibroblasts tested. This effect was also reported for most of the treated patients and is mirrored in the survival data. In the patient group with disease-onset below 1 year of age, we observed a statistically-significant better survival for patients treated with riboflavin.

The RELIEF study: Tolerability and efficacy of preservative-free latanoprost in the treatment of glaucoma or ocular hypertension

Purpose:

To assess tolerability and efficacy following a switch from benzalkonium chloride–latanoprost to preservative-free latanoprost in patients with glaucoma or ocular hypertension.

Methods:

A total of 140 patients with glaucoma or ocular hypertension controlled with benzalkonium chloride-latanoprost for at least 3 months were switched to treatment with preservative-free latanoprost. Assessments were made on days 15, 45, and 90 (D15, D45, and D90) and included best-corrected visual acuity, intraocular pressure, slit lamp examination, fluorescein staining, tear film break-up time, patient symptom evaluation, and subjective estimation of tolerability.

Results:

Mean best-corrected visual acuity remained unchanged during the study. Mean intraocular pressure compared with baseline (D0) remained stable throughout the study (D0, 15.9 mmHg (standard deviation = 2.6); D90, 15.3 mmHg (standard deviation = 2.4); p < 0.006). Tear film break-up time improved or remained unchanged relative to baseline in 92% of patients at D45 and in 93% at D90. Moderate-to-severe conjunctival hyperemia was seen in 56.8% of patients at D0, but this figure decreased to 13.7%, 2.2%, and 1.6% at D15, D45, and D90, respectively. Subjective assessment of tolerability (0–10 scale) indicated improvement with change of therapy (mean score: 5.3 (standard deviation = 2.2) at D0 versus 1.9 (standard deviation = 1.7) at D90; p < 0.0001).

Conclusion:

Preservative-free latanoprost has at least the same intraocular pressure-lowering efficacy as benzalkonium chloride–latanoprost, with a better tolerability profile. This may translate into greater control of treatment and improved quality of life.

NDUFB8 Mutations Cause Mitochondrial Complex I Deficiency in Individuals with Leigh-like Encephalomyopathy

Respiratory chain complex I deficiency is the most frequently identified biochemical defect in childhood mitochondrial diseases. Clinical symptoms range from fatal infantile lactic acidosis to Leigh syndrome and other encephalomyopathies or cardiomyopathies. To date, disease-causing variants in genes coding for 27 complex I subunits, including 7 mitochondrial DNA genes, and in 11 genes encoding complex I assembly factors have been reported. Here, we describe rare biallelic variants in NDUFB8 encoding a complex I accessory subunit revealed by whole-exome sequencing in two individuals from two families. Both presented with a progressive course of disease with encephalo(cardio)myopathic features including muscular hypotonia, cardiac hypertrophy, respiratory failure, failure to thrive, and developmental delay. Blood lactate was elevated. Neuroimaging disclosed progressive changes in the basal ganglia and either brain stem or internal capsule. Biochemical analyses showed an isolated decrease in complex I enzymatic activity in muscle and fibroblasts. Complementation studies by expression of wild-type NDUFB8 in cells from affected individuals restored mitochondrial function, confirming NDUFB8 variants as the cause of complex I deficiency. Hereby we establish NDUFB8 as a relevant gene in childhood-onset mitochondrial disease.

Clinical and molecular characteristics of newly reported mitochondrial disease entity caused by biallelic PARS2 mutations

Most of the 19 mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) involved in mitochondrial protein synthesis are already linked to specific entities, one of the exceptions being PARS2 mutations for which pathogenic significance is not finally validated. The aim of the study was to characterize the PARS2- related phenotype.Three siblings with biallelic PARS2 mutations presented from birth with infantile spasms, secondary microcephaly, and similar facial dysmorphy. Mental development was deeply impaired with speech absence and no eye contact. A dilated cardiomyopathy and multiorgan failure developed in childhood at the terminal stage, together with mitochondrial dysfunction triggered by valproate administration.Brain MRI showed progressive volume loss of the frontal lobes, both cortical and subcortical, with widening of the cortical sulci and frontal horns of the lateral ventricles. Hypoplasia of the corpus callosum and progressive demyelination were additional findings. Similar brain features were seen in three already reported PARS2 patients and seemed specific for this defect when compared with other mt-aaRSs defects (DARS2, EARS2, IARS2, and RARS2).Striking resemblance of the phenotype and Alpers-like brain MRI changes with predominance of frontal cerebral volume loss (FCVL-AS) in six patients from three families of different ethnicity with PARS2 mutations, justifies to distinguish the condition as a new disease entity.

Leigh syndrome in individuals bearing m.9185T>C MTATP6 variant. Is hyperventilation a factor which starts its development?

Leigh syndrome (LS), subacute necrotizing encephalomyelopathy is caused by various genetic defects, including m.9185T>C MTATP6 variant. Mechanism of LS development remains unknown. We report on the acid-base status of three patients with m.9185T>C related LS. At the onset, it showed respiratory alkalosis, reflecting excessive respiration effort (hyperventilation with low pCO₂). In patient 1, the deterioration occurred in temporal relation to passive oxygen therapy. To the contrary, on the recovery, she demonstrated a relatively low respiratory drive, suggesting that a "hypoventilation" might be beneficial for m.9185T>C carriers. As long as circumstances of the development of LS have not been fully explained, we recommend to counteract hyperventilation and carefully dose oxygen in patients with m.9185T>C related LS.

Virginal breast hypertrophy in a patient with Beckwith-Wiedemann syndrome

Virginal breast hypertrophy is a multidisciplinary condition including surgical, pediatric, and endocrine/gynecological disciplines, and its successful diagnosis and management requires complex, team approach.

Polish Experience with Liver Transplantation and Post-Transplant Outcomes in Children with Urea Cycle Disorders

BACKGROUND Liver transplantation (LT) is recommended for various metabolic diseases, including urea cycle disorders (UCDs). The aim of this study was to determine indications and outcomes of LT for UCDs in the tertiary reference Children's Hospital in Warsaw, Poland. MATERIAL AND METHODS Medical charts of children with UCD who underwent LT between 2008 and July 2016 were retrospectively reviewed. The following parameters were analyzed: symptoms at time of diagnosis, age at diagnosis, age at transplantation, graft characteristics and survival, postsurgical complications, and biochemical and laboratory results before and after transplantation. RESULTS Twelve patients with UCD who underwent LT at a mean age of 5 y (0.5-14 y) received a total of 14 liver grafts. Four children (33%) received a living donor graft, while 8 (68%) got a deceased donor liver graft. A total number of transplanted organs consisted of 9 (64%) whole-liver grafts and 5 (36%) reduced-size grafts. The 30-day post-transplant patient survival rate was 100% and graft survival rate was 93% (13/14). For those with a post-transplant follow-up of at least 1 year (n=10/12), the 1-year patient survival rate was 100% and the graft survival rate was 85.7% (12/14). Median peak of blood ammonia at presentation was 653 (159-2613) µg/dL (normal <80 µg/dl), and median peak of blood glutamine was 1273.2 µmol/l (964-3900 µmol/l). There was 1 episode of hyperammonemia following LT, but it was not due to UCD. Six (50%) patients were diagnosed with some degree of developmental delay/neurological impairment before transplantation, which remained stable or slightly improved after transplantation. Patients without developmental delay before transplantation maintained their cognitive abilities at follow-up. CONCLUSIONS LT leads to eradication of hyperammonemia, withdrawal of dietary restrictions with low-protein diet, and potentially improved neurocognitive development.

Biallelic mutations in CYP24A1 or SLC34A1 as a cause of infantile idiopathic hypercalcemia (IIH) with vitamin D hypersensitivity: molecular study of 11 historical IIH cases

Idiopathic infantile hypercalcemia (IIH) is a mineral metabolism disorder characterized by severe hypercalcemia, failure to thrive, vomiting, dehydration, and nephrocalcinosis. The periodical increase in incidence of IIH, which occurred in the twentieth century in the United Kingdom, Poland, and West Germany, turned out to be a side effect of rickets over-prophylaxis. It was recently discovered that the condition is linked to two genes, CYP24A1 and SLC34A1. The aim of the study was to search for pathogenic variants of the genes in adult persons who were shortlisted in infancy as IIH caused by “hypersensitivity to vit. D”. All persons were found to carry mutations in CYP24A1 or SLC34A1, nine and two persons respectively. The changes were biallelic, with one exception. Incidence of IIH in Polish population estimated on the basis of allele frequency of recurrent p.R396W CYP24A1 variant, is 1:32,465 births. It indicates that at least a thousand homozygotes and compound heterozygotes with risk of IIH live in the country. Differences in mechanism of developing hypercalcemia indicate that its prevention may vary in both IIH defects. Theoretically, vit. D restriction is a first indication for CYP24A1 defect (which disturbs 1,25(OH)₂D degradation) and phosphate supplementation for SLC34A1 defect (which impairs renal phosphate transport). In conclusion, we suggest that molecular testing for CYP24A1 and SLC34A1 mutations should be performed in each case of idiopathic hypercalcemia/hypercalciuria, both in children and adults, to determine the proper way for acute treatment and complications prevention.

NAXE Mutations Disrupt the Cellular NAD(P)HX Repair System and Cause a Lethal Neurometabolic Disorder of Early Childhood

To safeguard the cell from the accumulation of potentially harmful metabolic intermediates, specific repair mechanisms have evolved. APOA1BP, now renamed NAXE, encodes an epimerase essential in the cellular metabolite repair for NADHX and NADPHX. The enzyme catalyzes the epimerization of NAD(P)HX, thereby avoiding the accumulation of toxic metabolites. The clinical importance of the NAD(P)HX repair system has been unknown. Exome sequencing revealed pathogenic biallelic mutations in NAXE in children from four families with (sub-) acute-onset ataxia, cerebellar edema, spinal myelopathy, and skin lesions. Lactate was elevated in cerebrospinal fluid of all affected individuals. Disease onset was during the second year of life and clinical signs as well as episodes of deterioration were triggered by febrile infections. Disease course was rapidly progressive, leading to coma, global brain atrophy, and finally to death in all affected individuals. NAXE levels were undetectable in fibroblasts from affected individuals of two families. In these fibroblasts we measured highly elevated concentrations of the toxic metabolite cyclic-NADHX, confirming a deficiency of the mitochondrial NAD(P)HX repair system. Finally, NAD or nicotinic acid (vitamin B3) supplementation might have therapeutic implications for this fatal disorder.

Biallelic Mutations in TMEM126B Cause Severe Complex I Deficiency with a Variable Clinical Phenotype

Complex I deficiency is the most common biochemical phenotype observed in individuals with mitochondrial disease. With 44 structural subunits and over 10 assembly factors, it is unsurprising that complex I deficiency is associated with clinical and genetic heterogeneity. Massively parallel sequencing (MPS) technologies including custom, targeted gene panels or unbiased whole-exome sequencing (WES) are hugely powerful in identifying the underlying genetic defect in a clinical diagnostic setting, yet many individuals remain without a genetic diagnosis. These individuals might harbor mutations in poorly understood or uncharacterized genes, and their diagnosis relies upon characterization of these orphan genes. Complexome profiling recently identified TMEM126B as a component of the mitochondrial complex I assembly complex alongside proteins ACAD9, ECSIT, NDUFAF1, and TIMMDC1. Here, we describe the clinical, biochemical, and molecular findings in six cases of mitochondrial disease from four unrelated families affected by biallelic (c.635G>T [p.Gly212Val] and/or c.401delA [p.Asn134Ilefs^∗2]) TMEM126B variants. We provide functional evidence to support the pathogenicity of these TMEM126B variants, including evidence of founder effects for both variants, and establish defects within this gene as a cause of complex I deficiency in association with either pure myopathy in adulthood or, in one individual, a severe multisystem presentation (chronic renal failure and cardiomyopathy) in infancy. Functional experimentation including viral rescue and complexome profiling of subject cell lines has confirmed TMEM126B as the tenth complex I assembly factor associated with human disease and validates the importance of both genome-wide sequencing and proteomic approaches in characterizing disease-associated genes whose physiological roles have been previously undetermined.

New perspective in diagnostics of mitochondrial disorders: two years' experience with whole-exome sequencing at a national paediatric centre

Background

Whole-exome sequencing (WES) has led to an exponential increase in identification of causative variants in mitochondrial disorders (MD).

Methods

We performed WES in 113 MD suspected patients from Polish paediatric reference centre, in whom routine testing failed to identify a molecular defect. WES was performed using TruSeqExome enrichment, followed by variant prioritization, validation by Sanger sequencing, and segregation with the disease phenotype in the family.

Results

Likely causative mutations were identified in 67 (59.3 %) patients; these included variants in mtDNA (6 patients) and nDNA: X-linked (9 patients), autosomal dominant (5 patients), and autosomal recessive (47 patients, 11 homozygotes). Novel variants accounted for 50.5 % (50/99) of all detected changes. In 47 patients, changes in 31 MD-related genes (ACAD9, ADCK3, AIFM1, CLPB, COX10, DLD, EARS2, FBXL4, MTATP6, MTFMT, MTND1, MTND3, MTND5, NAXE, NDUFS6, NDUFS7, NDUFV1, OPA1, PARS2, PC, PDHA1, POLG, RARS2, RRM2B, SCO2, SERAC1, SLC19A3, SLC25A12, TAZ, TMEM126B, VARS2) were identified. The ACAD9, CLPB, FBXL4, PDHA1 genes recurred more than twice suggesting higher general/ethnic prevalence. In 19 cases, variants in 18 non-MD related genes (ADAR, CACNA1A, CDKL5, CLN3, CPS1, DMD, DYSF, GBE1, GFAP, HSD17B4, MECP2, MYBPC3, PEX5, PGAP2, PIGN, PRF1, SBDS, SCN2A) were found. The percentage of positive WES results rose gradually with increasing probability of MD according to the Mitochondrial Disease Criteria (MDC) scale (from 36 to 90 % for low and high probability, respectively). The percentage of detected MD-related genes compared with non MD-related genes also grew with the increasing MD likelihood (from 20 to 97 %). Molecular diagnosis was established in 30/47 (63.8 %) neonates and in 17/28 (60.7 %) patients with basal ganglia involvement. Mutations in CLPB, SERAC1, TAZ genes were identified in neonates with 3-methylglutaconic aciduria (3-MGA) as a discriminative feature. New MD-related candidate gene (NDUFB8) is under verification.

Conclusions

We suggest WES rather than targeted NGS as the method of choice in diagnostics of MD in children, including neonates with 3-MGA aciduria, who died without determination of disease cause and with limited availability of laboratory data. There is a strong correlation between the degree of MD diagnosis by WES and MD likelihood expressed by the MDC scale.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0930-9) contains supplementary material, which is available to authorized users.

Difficulties in recognition of pyruvate dehydrogenase complex deficiency on the basis of clinical and biochemical features. The role of next-generation sequencing

Pyruvate dehydrogenase complex (PDHc) defect is a well-known cause of mitochondrial disorders (MD) with at least six responsible genes (PDHA1, PDHB, DLAT, DLD, PDHX, PDP1). The aim of this work was to assess the diagnostic value of biochemical methods in recognition of PDHc defect in Polish patients with suspicion of MD.

In the first step, Western blot of the E1α subunit was performed on 86 archive muscle bioptates with suspicion of MD. In the second step, Sanger PDHA1 sequencing was performed in 21 cases with low E1α expression. In the third step, 7 patients with negative results of PDHA1 sequencing were subjected to whole-exome sequencing (WES). This protocol revealed 4 patients with PDHA1 and one with DLD mutations. Four additional probands were diagnosed outside the protocol (WES or Sanger sequencing).

The molecular characterization of PDHc defect was conducted in a total of 9 probands: 5 according to and 4 off the protocol. Additionally, two affected relatives were recognized by a family study. Altogether we identified seven different PDHA1 changes, including two novel variants [c.464T > C (p.Met155Thr) and c.856_859dupACTT (p.Arg288Leufs*10)] and one DLD variant.

The lactate response to glucose load in the PDHA1 subset was compared to a subset of non PDHc-related MD. Opposite responses were observed, with an increase of 23% and decrease of 27%, respectively.

The results show that determining lactate response to glucose load and muscle E1α expression may contribute to distinguishing PDHc-related and other MD, however, WES is becoming the method of choice for MD diagnostics.

Clinical pattern, mutations and in vitro residual activity in 33 patients with severe 5, 10 methylenetetrahydrofolate reductase (MTHFR) deficiency

BACKGROUND

Severe methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare inborn defect disturbing the remethylation of homocysteine to methionine (<200 reported cases). This retrospective study evaluates clinical, biochemical genetic and in vitro enzymatic data in a cohort of 33 patients.

METHODS

Clinical, biochemical and treatment data was obtained from physicians by using a questionnaire. MTHFR activity was measured in primary fibroblasts; genomic DNA was extracted from cultured fibroblasts.

RESULTS

Thirty-three patients (mean age at follow-up 11.4 years; four deceased; median age at first presentation 5 weeks; 17 females) were included. Patients with very low (<1.5%) mean control values of enzyme activity (n = 14) presented earlier and with a pattern of feeding problems, encephalopathy, muscular hypotonia, neurocognitive impairment, apnoea, hydrocephalus, microcephaly and epilepsy. Patients with higher (>1.7-34.8%) residual enzyme activity had mainly psychiatric symptoms, mental retardation, myelopathy, ataxia and spasticity. Treatment with various combinations of betaine, methionine, folate and cobalamin improved the biochemical and clinical phenotype. During the disease course, patients with very low enzyme activity showed a progression of feeding problems, neurological symptoms, mental retardation, and psychiatric disease while in patients with higher residual enzyme activity, myelopathy, ataxia and spasticity increased. All other symptoms remained stable or improved in both groups upon treatment as did brain imaging in some cases. No clear genotype-phenotype correlation was obvious.

DISCUSSION

MTHFR deficiency is a severe disease primarily affecting the central nervous system. Age at presentation and clinical pattern are correlated with residual enzyme activity. Treatment alleviates biochemical abnormalities and clinical symptoms partially.

[Effect of 0.1% diclofenac ophthalmic solution on inflammatory response and macular thickness following phacoemulsification cataract surgery]

PURPOSE

To evaluate 0.1% diclofenac sodium as an adjunctive therapy with loteprednol etabonate on postoperative inflammation in the anterior chamber and on foveal and parafoveal retinal thickness.

MATERIAL AND METHODS

Eighty eyes eligible for phacoemulsification were enrolled in a randomized clinical trial. Patients in group I (N = 40) received anti-inflammatory treatment consisting of 0.1% diclofenac with 0.5% loteprednol; group II (N = 40) patients received 0.5% loteprednol alone. Best corrected visual acuity and intraocular pressure were measured, and laser flarephotometry was done. Foveal and parafoveal thickness were assessed by optical coherence tomography. Results: Median flare values decreased more rapidly in group I at 7 and 14 days (7.9 and 7.4 ph/ms, respectively) than in group II (13.7 and 11.8 ph/ms, respectively; p < 0.0001). Group II had significantly increased parafoveal thickness at 14 and 42 days (median 285.59 μm, p = 0.001 and 288.38 μm, p < 0.001, respectively). Parafoveal thickness differed significantly between groups at 14 and 42 days (p = 0.0085, p = 0.0004, respectively).

CONCLUSIONS

Eyes treated with both diclofenac sodium and loteprednol etabonate showed less inflammatory response and were less likely to develop foveal and parafoveal thickening than those treated with steroid only.

Outcomes of oral biotin treatment in patients with biotinidase deficiency - Twenty years follow-up

INTRODUCTION

Biotinidase deficiency (BTD) is an inborn error of biotin metabolism inherited as an autosomal recessive trait. Due to the, biotinidase deficiency, biotin is not recycled. Individuals with BTD usually exhibit neurological and cutaneous abnormalities unless treated with biotin. Supplementation with biotin may either ameliorate or if early introduced even prevent symptoms when introduced presymptomatically.

PATIENTS AND METHODS

Since 1991, 22 Polish patients from 19 families have been diagnosed with BTD. In 16 children the diagnosis had been suspected on the basis of clinical signs: skin lesions, hyperventilation, seizures, spasticity, and laboratory investigation (elevated lactate and metabolites on urine organic acids profile). The defect was enzymatically (serum biotinidase activity measurement) and genetically (tested for mutations in the BTD gene) confirmed afterwards. All patients were treated with biotin. Urine organic acids analysis (GC/MS) for 3-hydroxizovaleric acid was used for patients' monitoring. Neurological, audiological and ophthalmological evaluation has been conducted once a year.

RESULTS

In 5 symptomatic patients a progressive optic nerve atrophy had already been noted at the time of treatment initiation. In these patients sensorineural hearing loss has also been diagnosed despite biotin supplementation. Asymptomatic patients treated with biotin supplementation presented no signs or symptoms of BTD. Supplementation with biotin slows the progression of BTD in symptomatic patients, but does not reverse nerve atrophy. Nonetheless, introduction of the treatment with biotin during presymptomatic stage of the disease prevents the onset of symptoms including optic atrophy and hearing loss. Homozygosity for the p.Leu215Phe mutation in BTD gene seems to be frequent in patients from the North-Eastern region of Poland and is connected with the hearing loss.

CONCLUSION

Since the prognosis for individuals diagnosed with BTD is good, provided they are treated before symptoms occur, it is justified to add this metabolic disorder to the panel of conditions screened under the national newborn screening programme in Poland.

Tyrosinemia type III in an asymptomatic girl

Tyrosinemia type 3 (HT3) is a rare inborn error of tyrosine metabolism caused by mutations in the HPD gene encoding 4-hydroxyphenyl-pyruvate dioxygenase, which is transmitted in an autosomal recessive trait. The disorder is characterized by tyrosine accumulation in body fluids and massive excretion of tyrosine derivatives into urine (www.orpha.net). Since it is the least frequent form of tyrosinemia, only few cases with the variable but rather mild clinical features have been described so far.

We report an 11 year old girl presenting with no clinical symptoms and with normal mental development who has been diagnosed with HT3 through metabolic screening on the basis of elevated serum level of tyrosine ranging from 425 to 535 μmol/L (normal values: 29–86 μmol/L), and elevated urinary excretion of p-hydroxyphenyl derivatives confirmed genetically with the homozygous c.479A > G (p.Tyr160Cys) missense change in the HPD gene. The girl has been only presenting with recurrent proteinuria of unknown etiology. A phenylalanine- and tyrosine-restricted diet has never been administered.

Presented case may suggest that high tyrosine concentration itself does not participate directly in neuronal damage described in patients with tyrosinemia type 3.

Treatment of Massive Labial and Gingival Hypertrophy in a Patient With Infantile Systemic Hyalinosis-A Case Report

Infantile systemic hyalinosis (ISH) is a rare autosomal recessive disorder caused by a mutation in the ANTXR2 gene encoding a transmembranous protein involved in endothelial development. The ANTXR2 (also known as CMG2) locus is on chromosome 4q21. ISH is a common disorder in children of consanguineous parents in Arab countries. Symptoms of ISH manifest within the first months of life as progressive painful joint contractures and edema, hyperpigmentation of the skin, cutaneous nodules, persistent diarrhea with protein-losing enteropathy, and recurrent infections. Children affected by ISH often die undiagnosed in infancy. Histopathologic examination shows hyaline deposits in the skin, skeletal muscles, cardiac muscle, lymph nodes, adrenal glands, gastrointestinal tract, thyroid, and spleen. Hyaline deposits are the result of leakage of plasma components to the perivascular space owing to defective endothelial morphogenesis. ISH manifests most often in the facial region. Patients develop hypertrophy of labial and buccal tissues and massive gingival overgrowths, which impair oral food intake and maintenance of satisfactory oral hygiene. The differential diagnosis of ISH should consider juvenile systemic hyalinosis (an allelic variant of ISH), Winchester syndrome, systemic fibromatosis, stiff skin syndrome, lipoid proteinosis, mucopolysaccharidosis, sphingolipidosis, and mucolipidosis. This report describes a case of massive labial and gingival hypertrophy in a 6-year-old boy with ISH.

Pediatric patient with hyperketotic hypoglycemia diagnosed with glycogen synthase deficiency due to the novel homozygous mutation in GYS2

BACKGROUND

Glycogen synthase deficiency (glycogen storage disease 0 - GSD 0) caused by mutations in the GYS2 gene is characterized by a lack of glycogen synthesis in the liver. It is a rare condition of disturbed glycogen homeostasis in the liver with less than 30 cases reported in the literature so far.

CASE REPORT

We report a 9 year old boy diagnosed with GSD 0 due to the newly identified, highly pathogenic homozygous mutation: NM_021957.3:p.Phe574Leu/c.1720T > C in ex. 14. A random, asymptomatic hypoglycemia with ketonuria was found in this patient at the age of 7. His developmental parameters were within normal ranges. Oral glucose tolerance test showed normal baseline blood levels of glucose, insulin and lactate, and their increase following glucose intake. Eight-hour fasting plasma glucose test, revealed glucose blood level of 34 mg/dl with no clinical symptoms. The results of these tests suggested GSD 0. Molecular analysis of the GYS2 gene was not feasible, but this particular gene was included in the panel of hypoglycemia of whole exome sequencing (WES) which was at our disposal.

Pregnancy delivery and puerperium in a patient with lysinuric protein intolerance--a case report

The paper presents the course of pregnancy delivery and early postpartum period in a 23-year-old woman with lysinuric protein intolerance (LPI). The pregnancy was uneventful and resulted in a caesarean birth to a healthy baby at 37 weeks gestation. Nevertheless, the course of pregnancy in women with LPI is associated with a significantly increased risk of serious complications, including acute hyperammonemia, preeclampsia and postpartum bleeding, as well as fetus intrauterine growth retardation. In many cases, intensive metabolic monitoring and a proper diet with protein limitation and appropriate amino acids supplementation may significantly reduce the risk for both the mother and the newborn.