An expanded clinical spectrum of hypoinsulinaemic hypoketotic hypoglycaemia.

BACKGROUND: Hypoketotic hypoglycaemia with suppressed plasma fatty acids and detectable insulin suggests congenital hyperinsulinism (CHI). Severe hypoketotic hypoglycaemia mimicking hyperinsulinism but without detectable insulin has recently been described in syndromic individuals with mosaic genetic activation of post-receptor insulin signalling. We set out to expand understanding of this entity focusing on metabolic phenotypes. METHODS: Metabolic profiling, candidate gene and exome sequencing were performed in six infants with hypoketotic, hypoinsulinaemic hypoglycaemia, with or without syndromic features. Additional signalling studies were carried out in dermal fibroblasts from two individuals. RESULTS: Two infants had no syndromic features. One was mistakenly diagnosed with CHI. One had mild features of megalencephaly-capillary malformation-polymicrogyria (MCAP) syndrome, one had non-specific macrosomia, and two had complex syndromes. All required intensive treatment to maintain euglycaemia, with CHI-directed therapies being ineffective. Pathogenic PIK3CA variants were found in two individuals - de novo germline c.323G>A (p.Arg108His) in one non-syndromic infant and postzygotic mosaic c.2740G>A (p.Gly914Arg) in the infant with MCAP. No causal variants were proven in the other individuals despite extensive investigation, although rare variants in mTORC components were identified in one. No increased PI3K signalling in fibroblasts of two individuals was seen. CONCLUSIONS: We expand the spectrum of PI3K-related hypoinsulinaemic hypoketotic hypoglycaemia. We demonstrate that pathogenic germline variants activating post-insulin-receptor signalling may cause non-syndromic hypoinsulinaemic hypoketotic hypoglycaemia closely resembling CHI. This distinct biochemical footprint should be sought and differentiated from CHI in infantile hypoglycaemia. To facilitate adoption of this differential diagnosis, we propose the term "pseudohyperinsulinism".

["Crazy bitch!"-Experienced aggression and violence in the daily clinical routine of pediatricians]. / "Crazy bitch!" ­ Erlebte Aggression und Gewalt im Klinikalltag von Kinderärzten.

Background: The indications for experienced aggression and violence towards doctors in children's hospitals are increasing and are the focus of this study. They are reported in contact with parents or relatives in emotionally highly charged situations caused by their child's illness. This empirical study investigated the extent to which experienced aggressive and violent behavior has been received by pediatricians in their everyday work in hospitals. Methods: Data from two previously unpublished nationwide surveys in 2009 (n = 160) and 2017 (n = 190) were analyzed. Using the same questionnaire, the forms of aggressive action, such as exerting pressure, insulting, threatening physical violence, attempting to use violence and actually using violence as well as the descriptions of the associated situations were questioned. The wording of the insults and the type of threat could be specified via open questions. Results: Approximately four out of five respondents said they have been the target of an aggressive action by parents or relatives. In 2017 approximately 3 out of 4 respondents (71.0%) considered the problem of aggressive behavior to be relevant to their everyday work compared to only every second respondent (51.9%) in 2009. Individual respondents reported up to 60 situations, in both survey waves at a median of 4.0 times per year. Conclusion: Experienced aggression and violence are often and increasingly part of everyday clinical life in the pediatric wards, ranging from insults to physical violence. Prevention strategies, such as preventive training for communication and de-escalation are explicitly desired.

A mutation in mannose-phosphate-dolichol utilization defect 1 reveals clinical symptoms of congenital disorders of glycosylation type I and dystroglycanopathy.

Congenital disorders of glycosylation type I (CDG-I) are inborn errors of metabolism, generally characterized by multisystem clinical manifestations, including developmental delay, hepatopathy, hypotonia, and skin, skeletal, and neurological abnormalities. Among others, dolichol-phosphate-mannose (DPM) is the mannose donor for N-glycosylation as well as O-mannosylation. DOLK-CDG, DPM1-CDG, DPM2-CDG, and DPM3-CDG are defects in the DPM synthesis showing both CDG-I abnormalities and reduced O-mannosylation of alpha-dystroglycan (αDG), which leads to muscular dystrophy-dystroglycanopathy. Mannose-phosphate-dolichol utilization defect 1 (MPDU1) plays a role in the utilization of DPM. Here, we report two MPDU1-CDG patients without skin involvement, but with massive dilatation of the biliary duct system and dystroglycanopathy characteristics including hypotonia, elevated creatine kinase, dilated cardiomyopathy, buphthalmos, and congenital glaucoma. Biochemical analyses revealed elevated disialotransferrin in serum, and analyses in fibroblasts showed shortened lipid linked oligosaccharides and DPM, and reduced O-mannosylation of αDG. Thus, MPDU1-CDG can be added to the list of disorders with overlapping biochemical and clinical abnormalities of CDG-I and dystroglycanopathy. SYNOPSIS: Mannose-phosphate-dolichol utilization defect 1 patients can have overlapping biochemical and clinical abnormalities of congenital disorders of glycosylation type I and dystroglycanopathy.

Inconsistencies in the management of neonates born to mothers with "thyroid diseases".

Although thyroid medications are frequently prescribed during pregnancy, paediatricians treating the respective neonates often have no information about the underlying maternal thyroid disease, and inconsistencies in postnatal diagnostics may result. We analysed a cohort of 1819 mothers admitted for delivery in 1 year to one hospital. We analysed the pre- and postpartum diagnostics in the mothers, the postnatal diagnostics in the neonates and their postnatal auxological development. Two hundred thirteen mothers (11.7%) had "thyroid disease"; 37 (2.0%) had Hashimoto thyroiditis, seven (0.4%) Graves' disease and 169 (9.3%) "thyroid disease of other origins". One hundred eighty-eight out of 213 (88%, 10.3% of the entire cohort) took levothyroxine. Pre- and postpartum diagnostics of the mothers and postnatal diagnostics of the neonates revealed striking inconsistencies. For example, 39 % of the gynaecologists routinely determined TSH, while only 59% carried out a dosage adjustment for known hypothyroidism. Second specialists were consulted in 86%. Unnecessary postpartum diagnostics were initiated in 19/213 neonates (9%). TRAb was analysed, however, in only one neonate born from the mothers with Graves' disease-a condition in which further diagnostic efforts are mandatory.Conclusion: Although many pregnant women have thyroid dysfunction, we observed a lack of uniformity in the diagnostic approach of the women and their neonates. What is Known: • Disturbed maternal thyroid function in pregnancy often has an adverse impact on both the mother and the foetus. • Although detailed guidelines for managing impaired maternal thyroid function during pregnancy have been published, their application in clinical practice varies widely. What is New: • Recommendations for managing the newborn of a mother presenting with thyroid disease of unknown entity are remarkably inconsistent. • This leads to a possible over-diagnosis in general and a potentially life-threatening failure to note neonatal hyperthyroidism requiring rapid treatment.

Skin conductance in neonates suffering from abstinence syndrome and unexposed newborns.

UNLABELLED: The aims of this study were to compare the skin conductance (SC) of newborns with opiate-induced neonatal abstinence syndrome (NAS) to that of unexposed newborns and to evaluate the potential of SC readings to detect distress in the context of NAS objectively. The SC of 12 newborns with NAS and 12 unexposed newborns was measured at nine specific times during their first 6 weeks of life. The number of SC fluctuations per second (NSCF/s), the amplitude of SC fluctuation, and the mean level of SC were recorded and analyzed. The SC of newborns treated for symptoms of NAS differed significantly from the SC of unexposed newborns with regard to the NSCF/s (p = 0.04). With the mean level of SC, we observed an interaction between groups over time (p value for interaction = 0.02). With increasing postnatal age, we observed higher values in all three SC parameters. CONCLUSION: The NSCF/s and the mean level of SC appear to be suitable to reflect the distress of newborns suffering from NAS. As it is known that the sensitivity of SC increases with the level of stress experienced, its potential to indicate elevated stress levels in infants with NAS should be investigated in future studies evaluating different therapy regimens. WHAT IS KNOWN: • Skin conductance is a result of the filling of palmar and plantar sweat glands innervated by the sympathetic nervous system • Skin conductance can be used as a measure of stress and pain in newborns What is New: • Skin conductance of newborns with neonatal abstinence syndrome (NAS) differs significantly from the SC of non-substance-exposed newborns during the first 6 weeks of life • Skin conductance appears to reflect the increased distress of infants with NAS.

MKRN3 mutations in familial central precocious puberty.

Loss-of-function mutations in the gene encoding the makorin RING finger protein 3 (MKRN3) have recently been reported to underlie familial cases of central precocious puberty (CPP). The imprinted MKRN3 gene is expressed only from the paternal allele, and mutations inherited from the father affect boys and girls equally, which is in contrast to the known female preponderance in idiopathic CPP. By screening a series of 6 families and 1 male patient with idiopathic CPP, we identified 2 further families carrying loss-of-function mutations in MKRN3, the previously reported variant c.475_476insC (p.Ala162Glyfs*14) and a novel one, c.331G>T (p.Glu111*). We conclude that MKRN3 mutations appear to be a frequent cause of familial CPP and, considering the imprinted mode of inheritance, may also account for a certain proportion of isolated CPP cases. Remarkably, four out of six MKRN3 mutations described so far encode either a stop codon or a frameshift followed by a premature stop codon. Consequently, there may be less severe mutations that possibly associate with more subtle phenotypes, which could even explain variation within the physiological range. Mutation screening in larger cohorts is necessary in order to estimate the real prevalence of MKRN3 mutations in idiopathic CPP.

Perinatal and early infantile symptoms in congenital disorders of glycosylation.

Congenital disorders of glycosylation (CDG) are a rapidly growing family of inborn errors. Screening for CDG in suspected cases is usually performed in the first year of life by serum transferrin isoelectric focusing or mass spectrometry. Based on the transferrin analysis patients can be biochemically diagnosed with a type 1 or type 2 transferrin pattern, and labeled as CDG-I, or CDG-II. The diagnosis of CDG is frequently delayed due to the highly variable phenotype, some cases showing single organ involvement and others mimicking syndromes, like skeletal dysplasia, cutis laxa syndrome, or congenital muscle dystrophy. The aim of our study was to evaluate perinatal abnormalities and early discriminative symptoms in 58 patients consecutively diagnosed with diverse CDG-subtypes. Neonatal findings and clinical features in the first months of life were studied in 36 children with CDG-I and 22 with CDG-II. Maternal complications were found in five, small for gestational age in nine patients. Five children had abnormal neonatal screening results for hypothyroidism. Congenital microcephaly and neonatal seizures were common in CDG-II. Inverted nipples were uncommon with 5 out of 58 children. Dysmorphic features were mostly nonspecific, except for cutis laxa. Early complications included feeding problems, cardiomyopathy, thrombosis, and bleeding. Cases presenting in the neonatal period had the highest mortality rate. Survival in CDG patients is highly dependent on early intervention therapy. We recommend low threshold screening for glycosylation disorders in infants with neurologic symptoms, even in the absence of abnormal fat distribution. Growth retardation and neonatal bleeding increase suspicion for CDG.

Neonatal screening: identification of children with 11ß-hydroxylase deficiency by second-tier testing.

BACKGROUND: 21-Hydroxylase deficiency (21-OHD) is the target disease of newborn screening for congenital adrenal hyperplasia (CAH). We describe the additional detection of patients suffering from 11ß-hydroxylase deficiency (11-OHD) by second-tier testing. METHOD: Over a period of 5 years, screening for CAH was done in a total of 986,098 newborns by time-resolved immunoassay (DELFIA®) for 17α-hydroxyprogesterone (17-OHP). Positive samples were subsequently analyzed in an LC-MS/MS second-tier test including 17-OHP, cortisol, 11-deoxycortisol, 4-androstenedione and 21-deoxycortisol. RESULTS: In addition to 78 cases of 21-OHD, 5 patients with 11-OHD were identified. Diagnostic parameters were a markedly elevated concentration of 11-deoxycortisol in the presence of a low level of cortisol. Androstenedione was also increased. In contrast to 21-OHD, concentrations of 21-deoxycortisol were normal. CONCLUSION: Steroid profiling in newborn blood samples showing positive results in immunoassays for 17-OHP allows for differentiating 21-OHD from 11-OHD. This procedure may not detect all cases of 11-OHD in the newborn population because there may be samples of affected newborns with negative results for 17-OHP in the immunoassay.

Four novel mutations of the LHX3 gene cause combined pituitary hormone deficiencies with or without limited neck rotation.

CONTEXT: The Lhx3 LIM-homeodomain transcription factor gene is required for development of the pituitary and motoneurons in mice. Human LHX3 gene mutations have been reported in five subjects with a phenotype consisting of GH, prolactin, TSH, LH, and FSH deficiency; abnormal pituitary morphology; and limited neck rotation. OBJECTIVE: The objective of the study was to determine the frequency and nature of LHX3 mutations in patients with isolated GH deficiency or combined pituitary hormone deficiency (CPHD) and characterize the molecular consequences of mutations. DESIGN: The LHX3 sequence was determined. The biochemical properties of aberrant LHX3 proteins resulting from observed mutations were characterized using reporter gene and DNA binding experiments. PATIENTS: The study included 366 patients with isolated GH deficiency or CPHD. RESULTS: In seven patients with CPHD from four consanguineous pedigrees, four novel, recessive mutations were identified: a deletion of the entire gene (del/del), mutations causing truncated proteins (E173ter, W224ter), and a mutation causing a substitution in the homeodomain (A210V). The mutations were associated with diminished DNA binding and pituitary gene activation, consistent with observed hormone deficiencies. Whereas subjects with del/del, E173ter, and A210V mutations had limited neck rotation, patients with the W224ter mutation did not. CONCLUSIONS: LHX3 mutations are a rare cause of CPHD involving deficiencies for GH, prolactin, TSH, and LH/FSH in all patients. Whereas most patients have a severe hormone deficiency manifesting after birth, milder forms can be observed, and limited neck rotation is not a universal feature of patients with LHX3 mutations. This study extends the known molecular defects and range of phenotypes found in LHX3-associated diseases.

A common mutation in the COG7 gene with a consistent phenotype including microcephaly, adducted thumbs, growth retardation, VSD and episodes of hyperthermia.

We describe the clinical and biochemical characteristics in three patients from two different families diagnosed with Congenital Disorder of Glycosylation type IIe owing to a defect in Conserved Oligomeric Golgi complex (COG)7; one of the eight subunits of the COG. The siblings and an unrelated single child of consanguineous parents presented with growth retardation, progressive, severe microcephaly, hypotonia, adducted thumbs, feeding problems by gastrointestinal pseudo-obstruction, failure to thrive, cardiac anomalies, wrinkled skin and episodes of extreme hyperthermia. A combined disorder in the biosynthesis of N- and O-linked glycosylation with hyposialylation was detected. Western blot analysis showed a severe reduction in the COG5 and 7 subunits of the COG. A homozygous, intronic splice site mutation (c.169+4A>C) of the COG7 gene was identified in all patients. The phenotype is similar to that previously described in two patients of North African ethnicity with the same mutation, except for the lack of skeletal anomalies and only a mild liver involvement in our patients. We suggest performing protein glycosylation studies and Western blot for the different COG subunits in patients with progressive microcephaly, growth retardation, hypotonia, adducted thumbs and cardiac defects, especially in association with skin anomalies or episodes of hyperthermia. The presence of the characteristic phenotype might warrant direct DNA analysis.

Congenital hypothyroidism caused by new mutations in the thyroid oxidase 2 (THOX2) gene.

OBJECTIVE: Congenital primary hypothyroidism (CH) occurs in one of 4000 births and in 20% of the cases CH is due to a defect in thyroid hormonogenesis. Candidate genes were examined to determine the precise aetiology of suspected dyshormonogenesis in CH. DESIGN: The genes that code for thyroid peroxidase (TPO), pendrin (PDS), sodium iodide symporter (NIS) and thyroid oxidase 2 (THOX2) were sequenced directly from genomic DNA. PATIENTS: Two girls found to have CH in the neonatal screening programme and suspected of having thyroid dyshormonogenesis were investigated to identify their molecular defect. RESULTS: Patient A had a novel heterozygous 1 bp insertion in the THOX2 gene (ins602g). This insertion results in a frameshift that predicts a premature stop at codon 300. Analysis of cDNA, transcribed from lymphocyte RNA, showed that this mutation causes skipping of exon 5, resulting in a frameshift and a premature stop at codon 254. The euthyroid mother was also a heterozygous carrier of the mutation whereas the father was homozygous for the wild-type THOX2 gene. In patient B, compound heterozygous mutations (ins602g-->fsX300 and D506N) were identified. D506N was present in one allele of the clinically unaffected mother and in a brother, whereas the euthyroid father was heterozygous for ins602g. Sixty normal individuals did not harbour the mutations. Sequencing of the TPO, PDS and NIS genes revealed no mutations. CONCLUSIONS: The identified THOX2 mutations, which have not been described previously, are the probable causes of CH in the patients. Mutations in the THOX2 gene should be considered as the molecular cause of CH in young patients with thyroid dyshormonogenesis.

Congenital adrenal hyperplasia due to 11-hydroxylase deficiency: functional characterization of two novel point mutations and a three-base pair deletion in the CYP11B1 gene.

Congenital adrenal hyperplasia is a group of autosomal recessive disorders second most often caused by deficiency of steroid 11-hydroxylase (CYP11B1) due to mutations in the CYP11B1 gene. We studied the functional and structural consequences of two novel missense mutations (W116C, L299P) and an in-frame 3-bp deletion (DeltaF438) in the CYP11B gene, detected in three unrelated families. All patients are suffering from classical CYP11B1 deficiency. In vitro expression studies in COS-7 cells revealed a decreased CYP11B1 activity in the W116C mutant to 2.9 +/- 0.9% (sd) for the conversion of 11-deoxycortisol to cortisol. The L299P mutant reduced the enzymatic activity to 1.2 +/- 0.9%, whereas the DeltaF438 mutation resulted in no measurable residual CYP11B1 activity. Introduction of these mutations in a three-dimensional model structure of the CYP11B1 protein provides a possible explanation for the in vitro measured effects. We hypothesize that the W116C mutation influences the conformational change of the 11-hydroxylase protein necessary for substrate access and product release. The L299P mutation causes a change in the position of the I helix relative to the heme group, whereas the DeltaF438 mutation results in a steric disarrangement of the heme group relative to the enzyme. Studying the enzyme function in vitro helps to understand the phenotypical expression and disease severity of 11-hydroxylase deficiency, which is the basis for accurate genetic counseling, prenatal diagnosis, and treatment. Moreover, the combination of in vitro enzyme function and molecular modeling provides new insights in cytochrome P450 structural-functional relationships.

Mosaic tetrasomy 14pter-q13 due to a supernumerary isodicentric derivate of proximal chromosome 14q.

Tetrasomy of proximal 14q is an extremely rare condition and has never been reported to be associated with survival. We here report on the first case of mosaic tetrasomy of 14pter-q13 due to a de-novo supernumerary pseudoisodicentric chromosome in a 2-year-old boy with multiple dysmorphisms and malformations. The marker was detectable in nearly 25% of lymphocytes as well as in cells from buccal mucosa. Detailed fluorescence in situ hybridization (FISH) analyses allowed the characterization of the marker to entirely consist of proximal 14q material and to be symmetric. The pattern of clinical features in our patient only slightly correspond to that of patients with trisomy of proximal 14q, but further cases are needed to define whether tetrasomy of proximal 14q is a separate entity.

Four new cases of congenital secondary hypothyroidism due to a splice site mutation in the thyrotropin-beta gene: phenotypic variability and founder effect.

Isolated TSH deficiency is a rare cause of congenital hypothyroidism. We here report four children from two consanguineous Turkish families with isolated TSH deficiency. Affected children who were screened at newborn age had an unremarkable TSH result and a low serum TSH level at diagnosis. Age at diagnosis and clinical phenotype were variable. All affected children carried an identical homozygous splice site mutation (IVS2 + 5 G--> A) in the TSHbeta gene. This mutation leads to skipping of exon 2 and a loss of the translational start codon without ability to produce a TSH-like protein. However, using specific monoclonal antibodies, we detected a very low concentration of authentic, heterodimeric TSH in serum, indicating the production of a small amount of correctly spliced TSH mRNA. By genotyping all family members with polymorphic markers at the TSHbeta locus, we show that the mutation arose on a common ancestral haplotype in three unrelated Turkish families indicating a founder mutation in the Turkish population. These results suggest that this TSHbeta mutation is among the more common TSHbeta gene mutations and stress the need for a biochemical and molecular genetic workup in children with symptoms suggestive of congenital hypothyroidism, even when the neonatal TSH screening is normal.