Secondary Hirata Syndrome in a Neonate: Practical Approach and Management.

Hirata disease, also known as insulin autoimmune syndrome (IAS), is a rare cause of hypoglycemia, due to the presence of insulin autoantibodies (IAA) in the circulating blood. These antibodies are immunoglobulin G (IgG), making placental transfer to the fetus possible. To our knowledge, no reports of IAS have been previously described in the neonatal population. We present a case report of hypoglycemia due to a secondary IAS in a neonate and discuss the management and treatment of the disease.

Diagnostic Accuracy of Lung Ultrasound in Neonatal Diseases: A Systematized Review.

Background: Respiratory problems are frequent in newborns, and are mainly studied with chest X-rays, whereas CT scans are usually needed for the evaluation of rare malformations and diseases. Lung ultrasound (LUS] has been proposed as an alternative method of diagnosing a variety of respiratory conditions. In recent years, there has been a rapid increase in LUS studies, thanks to the ability of LUS to rapidly exclude complications and significantly reduce radiation exposure in this fragile population. We aimed to summarize the current knowledge about LUS. Methods: A literature search was conducted on the Medline and Cochrane databases using appropriate terms. The inclusion criteria were: English language and human species. Exclusion criteria were: non-English language, animal species, case reports, case series, non-systematic reviews, and editorials. Results: The search returned 360 results. No Cochrane reviews were found. Titles and abstracts were screened, and 37 were finally considered. Studies concerning the use of lung ultrasound for the following conditions were presented: neonatal respiratory distress syndrome, transient tachypnea of the newborn, pneumothorax, pulmonary hemorrhage, pneumonia, bronchopulmonary dysplasia, and prediction of extubation success. Conclusions: We discussed the utility of LUS for the diagnosis and treatment of neonatal diseases according to the most recent literature.

Potential pathogenetic role of a novel ABCC8 missense variant on both transient neonatal diabetes mellitus and fetal growth restriction: a case report.

BACKGROUND: The diagnosis of neonatal diabetes can be problematic in preterm infants with fetal growth restriction (FGR). Growth restricted fetuses may have impaired insulin production and secretion; low birthweight infants may have a reduced response to insulin. We report a novel missense ABCC8 variant associated with a clinical phenotype compatible with transient neonatal diabetes mellitus (TNDM) in a fetal growth restricted preterm infant. METHODS AND RESULTS: A preterm growth restricted infant experienced hyperglycemia from the first day of life, requiring insulin therapy on the 13th and 15th day of life and leading to the diagnosis of TNDM. Glycemic values normalized from the 35th day of life onwards. Genetic screening was performed by next generation sequencing, using a Clinical Exon panel of 4800 genes, filtered for those associated with the clinical presentation and by means of methylation-specific multiplex ligation-dependent probe amplification analysis to identify chromosomal aberrations at 6q24. Genetic tests excluded defects at 6q24 and were negative for KCNJ11, SLC2A2 (GLUT-2) and HNF1B, but revealed the presence of the heterozygous missense variant c.2959T > C (p.Ser987Pro) in ABCC8 gene. The presence of the variant was excluded in parents' DNA and the proband variant was then considered de novo. CONCLUSIONS: In our infant, the persistence of hyperglycemia beyond 3 weeks of life led us to the diagnosis of TNDM and to hypothesize a possible genetic cause. The genetic variant we found could be, most likely, the main cause of both FGR and TNDM.

Real-Time Ultrasound Tip Location Reduces Malposition and Radiation Exposure during Umbilical Venous Catheter Placement in Neonates: A Retrospective, Observational Study.

INTRODUCTION: The umbilical venous catheter is a vital access device in neonatal intensive care units for preterm and critically ill infants. Correct positioning is crucial, as malpositioning can lead to severe complications. According to international guidelines, the position of the umbilical venous catheter tip must be assessed in real time; traditionally, the catheter is visualized with a thoracoabdominal X-ray, but one of the most effective and safest methods is therefore real-time ultrasound. METHODS: This study compares real-time ultrasound and traditional X-ray methods for assessing umbilical venous catheter tip location in 461 cases. The rate of tip malposition was analyzed retrospectively. The secondary aim was to assess indwelling time of umbilical venous catheters and reasons of removal. RESULTS: Real-time ultrasound tip location, found to be more reliable and efficient, demonstrated a significantly lower incidence of primary malpositioning compared to X-ray assessments (9.6 vs. 75.9%). The study also highlighted the association of real-time ultrasound with reduced catheter manipulation, fewer radiographs, and higher indwelling times of umbilical venous catheter. The multiple logistic regression showed a high probability of the central safe position of the umbilical venous catheter tip using real-time ultrasound tip location (odds ratio 29.5, 95% confidence interval: 17.4-49.4). CONCLUSION: The findings support the adoption of real-time ultrasound in clinical settings to enhance umbilical venous catheter placement accuracy and minimize associated risks. A minimal training investment is needed to attain the proficiency to visualize the umbilical venous catheters, offering a substantial advantage in terms of both cost-effectiveness for the procedure and enhanced patient safety.

Diaphragm atrophy during invasive mechanical ventilation is related to extubation failure in preterm infants: An ultrasound study.

BACKGROUND: Diaphragm dysfunction is associated with poor outcomes in critically ill patients. Ventilator-induced diaphragmatic dysfunction (VIDD), including diaphragm atrophy (DA), is poorly studied in newborns. We aimed to assess VIDD and its associations in newborns. METHODS: Single-center prospective study. Diaphragm thickness was measured at end-inspiration (TDI) and end-expiration (TDE) on the right midaxillary line. DA was defined as decrease in TDE ≥ 10%. Daily measurements were recorded in preterm newborns on invasive mechanical ventilation (IMV) for ≥2 days. Clinical characteristics of patients and extubation failure were recorded. Univariate analysis, logistic regression, and mixed models were performed to describe VIDD and associated factors. RESULTS: We studied 17 patients (median gestational age 270/7 weeks) and 22 IMV cycles (median duration 9 days). Median TDE decreased from 0.118 cm (interquartile range [IQR] 0.094-0.165) on the first IMV day to 0.104 cm (IQR 0.083-0.120) on the last IMV day (p = .092). DA occurred in 11 IMV cycles (50%) from 10 infants early during IMV (median: second IMV day). Mean airway pressure (MAP) and lung ultrasound score (LUS) on the first IMV day were significantly higher in patients who developed DA. DA was more frequent in patients with extubation failure than in those with extubation success within 7 days (83.3 vs. 33.3%, p = .038). CONCLUSIONS: DA, significantly associated with extubation failure, occurred in 58.8% of the study infants on IMV. Higher MAP and LUS at IMV start were associated with DA. Our results suggest a potential role of diaphragm ultrasound to assess DA and predict extubation failure in clinical practice.

Neonatal hypoglycemia and neurodevelopmental outcomes: Yesterday, today, tomorrow.

Neonatal hypoglycemia is a major source of concern for pediatricians since it has commonly been related to poor neurodevelopmental outcomes. Diagnosis is challenging, considering the different operational thresholds provided by each guideline. Screening of infants at risk plays a crucial role, considering that most hypoglycemic infants show no clinical signs. New opportunities for prevention and treatment are provided by the use of oral dextrose gel. Continuous glucose monitoring systems could be a feasible tool in the next future. Furthermore, there is still limited evidence to underpin the current clinical practice of administering, in case of hypoglycemia, an intravenous "mini-bolus" of 10% dextrose before starting a continuous dextrose infusion. This brief review provides an overview of the latest advances in this field and neurodevelopmental outcomes according to different approaches.   Conclusion: To adequately define if a more permissive approach is risk-free for neurodevelopmental outcomes, more research on continuous glucose monitoring and long-term follow-up is still needed. What is Known: • Neonatal hypoglycemia (NH) is a well-known cause of brain injury that could be prevented to avoid neurodevelopmental impairment. • Diagnosis is challenging, considering the different suggested operational thresholds for NH (<36, <40, <45, <47 or <50 mg/dl). What is New: • A 36 mg/dl threshold seems to be not associated with a worse psychomotor development at 18 months of life when compared to the "traditional" threshold (47 mg/dl). • Further studies on long-term neurodevelopmental outcomes are required before suggesting a more permissive management of NH.

Lung UltrasouNd Guided surfactant therapy in preterm infants: an international multicenter randomized control trial (LUNG study).

BACKGROUND: The management of respiratory distress syndrome (RDS) in premature newborns is based on different types of non-invasive respiratory support and on surfactant replacement therapy (SRT) to avoid mechanical ventilation as it may eventually result in lung damage. European guidelines currently recommend SRT only when the fraction of inspired oxygen (FiO2) exceeds 0.30. The literature describes that early SRT decreases the risk of bronchopulmonary dysplasia (BPD) and mortality. Lung ultrasound score (LUS) in preterm infants affected by RDS has proven to be able to predict the need for SRT and different single-center studies have shown that LUS may increase the proportion of infants that received early SRT. Therefore, the aim of this study is to determine if the use of LUS as a decision tool for SRT in preterm infants affected by RDS allows for the reduction of the incidence of BPD or death in the study group. METHODS/DESIGN: In this study, 668 spontaneously-breathing preterm infants, born at 25+0 to 29+6 weeks' gestation, in nasal continuous positive airway pressure (nCPAP) will be randomized to receive SRT only when the FiO2 cut-off exceeds 0.3 (control group) or if the LUS score is higher than 8 or the FiO2 requirements exceed 0.3 (study group) (334 infants per arm). The primary outcome will be the difference in proportion of infants with BPD or death in the study group managed compared to the control group. DISCUSSION: Based on previous published studies, it seems that LUS may decrease the time to administer surfactant therapy. It is known that early surfactant administration decreases BPD and mortality. Therefore, there is rationale for hypothesizing a reduction in BPD or death in the group of patients in which the decision to administer exogenous surfactant is based on lung ultrasound scores. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT05198375 . Registered on 20 January 2022.

Early Respiratory Physiotherapy versus an Individualized Postural Care Program for Reducing Mechanical Ventilation in Preterm Infants: A Randomised Controlled Trial.

BACKGROUND: Tactile stimulation manoeuvres stimulate spontaneous breathing in preterm newborns. The aim of this study is to evaluate the effect of early respiratory physiotherapy on the need for mechanical ventilation during the first week of life in preterm infants with respiratory failure. METHODS: This is a monocentric, randomised controlled trial. Preterm infants (gestational age ≤ 30 weeks) not intubated in the delivery room and requiring non-invasive respiratory support at birth were eligible for the study. The intervention group received early respiratory physiotherapy, while the control group received only a daily physiotherapy program (i.e., modifying the infant's posture in accordance with the patient's needs). RESULTS: between October 2019 and March 2021, 133 preterm infants were studied, 68 infants in the study group and 65 in routine care. The study group showed a reduction in the need for mechanical ventilation (not statistically significant) and a statistically significant reduction in hemodynamically significant patent ductus arteriosus with respect to the control group (19/68 (28%) vs. 35/65 (54%), respectively, p = 0.03). CONCLUSIONS: early respiratory physiotherapy in preterm infants requiring non-invasive respiratory support at birth is safe and has proven to be protective against haemodynamically significant PDA.

Bile Acids Pneumonia: A Respiratory Distress Syndrome in Early-Term Neonates.

Intrahepatic cholestasis of pregnancy (ICP) complicates among 0.2-2% of pregnancies and has been associated with adverse perinatal outcomes, including sudden stillbirth, meconium strained fluid, preterm birth, perinatal asphyxia, and transient tachypnea of the newborn. The diagnosis of "bile acids pneumonia" was previously proposed and a causative role of bile acids (BA) was supposed with a possible mechanism of action including surfactant dysfunction, inflammation, and chemical pneumonia. In the last few years, the role of lung ultrasound (LUS) in the diagnosis and management of neonatal respiratory distress syndrome has grown, and LUS scores have been introduced in the literature, as an effective predictor of the need for surfactant treatment among neonates with respiratory distress syndrome. We present four cases of infants born from pregnancies complicated by ICP, who developed respiratory distress syndrome early after birth. Lung ultrasound showed the same pattern for all infants, corresponding to a homogeneous alveolar-interstitial syndrome characterized by a diffuse coalescing B-line pattern (white lung). All infants evaluated require non-invasive respiratory support and in three cases surfactant administration, despite the near-term gestational age, with rapid improvement of respiratory disease and a good clinical outcome.

The Role of Ultrasound in Epicutaneo-Caval Catheter Insertion in Neonates: Systematic Review, Meta-Analysis and Future Perspectives.

Chest and abdominal X-rays after the insertion of an epicutaneo-caval catheter in infants are the standard method of checking the tip location in many neonatal intensive care units. The role of ultrasound in the tip location of the epicutaneo-caval catheter in neonates has been the subject of many recent studies. This systematic review investigates the accuracy of epicutaneo-caval catheter tip location by comparing ultrasound and conventional radiology. We performed a systematic literature search in multiple databases. The selection of studies yielded nineteen articles. The systematic review and meta-analysis were performed according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analysis). The analyses showed that ultrasound is a better imaging technique for epicutaneo-caval catheter tip location in the neonatal intensive care unit than conventional radiology. By improving operator training and selecting a standardized echography protocol, ultrasound could become the gold standard for visualizing the epicutaneo-caval catheter tip in the neonatal intensive care unit. This would have some important benefits: (1) increased accuracy in tip location (2); a more rapid use of the central venous access (3); and a significant reduction in radiation exposure.

The Utility and Safety of a Continuous Glucose Monitoring System (CGMS) in Asphyxiated Neonates during Therapeutic Hypothermia.

BACKGROUND: The present study was designed to assess the feasibility and reliability of a Continuous Glucose Monitoring System (CGMS) in a population of asphyxiated neonates during therapeutic hypothermia. METHODS: This non-randomized feasibility study was conducted in the Neonatal Intensive Care Unit (NICU) facilities of Fondazione Policlinico A. Gemelli IRCSS. Infants matching the criteria for hypothermic treatment were included in this study and were connected to the CGMS (Medtronic, Northridge, CA, USA) within the first 12 h of life. Hypoglycemia was defined as a glucose value ≤ 47 mg/dL, and hyperglycemia was defined as a glucose value ≥ 180 mg/dL. Data obtained via the CGMS were compared with those obtained via a point-of-care blood glucometer (GTX). RESULTS: The two measuring techniques were compared using the Modified Clarke Error Grid (MCEG). Sixteen infants were enrolled. The sensor had an average (standard deviation) duration of 93 (38) h. We collected 119 pairs of glycemia values (CGMVs) from the CGMS vs. GTX measurements. The CGMS detected twenty-five episodes of hypoglycemia and three episodes of hyperglycemia. All the CGMVs indicating hyperglycemia matched with the blood sample taken via the point-of-care glucometer. CONCLUSIONS: The use of a CGMS would be useful as it could detect more episodes of disglycemia than standard care. Our data show poor results in terms of the accuracy of the CGMS in this particular setting.

The future of neonatal lung ultrasound: Validation of an artificial intelligence model for interpreting lung scans. A multicentre prospective diagnostic study.

BACKGROUND: Artificial intelligence (AI) is a promising field in the neonatal field. We focused on lung ultrasound (LU), a useful tool for the neonatologist. Our aim was to train a neural network to create a model able to interpret LU. METHODS: Our multicentric, prospective study included newborns with gestational age (GA) ≥ 33 + 0 weeks with early tachypnea/dyspnea/oxygen requirements. For each baby, three LU were performed: within 3 h of life (T0), at 4-6 h of life (T1), and in the absence of respiratory support (T2). Each scan was processed to extract the region of interest used to train a neural network to classify it according to the LU score (LUS). We assessed sensitivity, specificity, positive and negative predictive value of the AI model's scores in predicting the need for respiratory assistance with nasal continuous positive airway pressure and for surfactant, compared to an already studied and established LUS. RESULTS: We enrolled 62 newborns (GA = 36 ± 2 weeks). In the prediction of the need for CPAP, we found a cutoff of 6 (at T0) and 5 (at T1) for both the neonatal lung ultrasound score (nLUS) and AI score (AUROC 0.88 for T0 AI model, 0.80 for T1 AI model). For the outcome "need for surfactant therapy", results in terms of area under receiver operator characteristic (AUROC) are 0.84 for T0 AI model and 0.89 for T1 AI model. In the prediction of surfactant therapy, we found a cutoff of 9 for both scores at T0, at T1 the nLUS cutoff was 6, while the AI's one was 5. Classification accuracy was good both at the image and class levels. CONCLUSIONS: This is, to our knowledge, the first attempt to use an AI model to interpret early neonatal LUS and can be extremely useful for neonatologists in the clinical setting.

Cord blood presepsin as a predictor of early-onset neonatal sepsis in term and preterm newborns.

BACKGROUND: To date, no studies on presepsin values in cord blood of term infants with risk factors for early-onset sepsis (EOS) are available, whereas only one study reported presepsin values in cord blood of preterm infants at risk. In this study, we investigated the presepsin values in cord blood of term and preterm infants with documented risk factors for EOS. METHODS: In this single-center prospective pilot study, we enrolled neonates presenting with documented risk factors for EOS. P-SEP levels were assessed in a blood sample collected from the clamped umbilical cord after the delivery in 93 neonates, using a point-of-care device. The primary outcome of our study was to evaluate the role of cord blood P-SEP in predicting clinical EOS in term and preterm infants. RESULTS: During the study period, we enrolled 93 neonates with risk factors for EOS with a gestational age ranging between 24.6 and 41.6 weeks (median 38.0). The median P-SEP value in all infants was 491 pg/ml (IQR 377 - 729). Median cord P-SEP values were significantly higher in infants with clinical sepsis (909 pg/ml, IQR 586 - 1307) rather than in infants without (467 pg/ml, IQR 369 - 635) (p = 0.010). We found a statistically significant correlation between cord P-SEP value at birth and the later diagnosis of clinical sepsis (Kendall's τ coefficient 0.222, p = 0.002). We identified the maximum Youden's Index (best cut-off point) at 579 pg/ml, corresponding to a sensitivity of 87.5% and a specificity of 71.8% in predicting clinical sepsis. CONCLUSIONS: Maximum Youden's index was 579 pg/ml for clinical EOS using cord P-SEP values. This could be the starting point to realize multicenter studies, confirming the feasibility of dosing P-SEP in cord blood of infants with risk factors of EOS to discriminate those who could develop clinical sepsis and spare the inappropriate use of antibiotics.

Lung Ultrasound in the Early Diagnosis and Management of the Mild Form of Meconium Aspiration Syndrome: A Case Report.

MAS is a common cause of neonatal respiratory distress in term and post-term neonates. Meconium staining of the amniotic fluid occurs in about 10-13% of normal pregnancies, and about 4% of these infants develop respiratory distress. In the past, MAS was diagnosed mainly on the basis of history, clinical symptoms, and chest radiography. Several authors have addressed the ultrasonographic assessment of the most common respiratory patterns in neonates. In particular, MAS is characterised by a heterogeneous alveolointerstitial syndrome, subpleural abnormalities with multiple lung consolidations, characterised by a hepatisation aspect. We present six cases of infants with a clinical history of meconium-stained fluid who presented with respiratory distress at birth. Lung ultrasound allowed the diagnosis of MAS in all the studied cases, despite the mild clinical picture. All children had the same ultrasound pattern with diffuse and coalescing B-lines, pleural line anomalies, air bronchograms, and subpleural consolidations with irregular shapes. These patterns were distributed in different areas of the lungs. These signs are specific enough to distinguish between MAS and other causes of neonatal respiratory distress, allowing the clinician to optimise therapeutic management.

Lowering of the Neonatal Lung Ultrasonography Score after nCPAP Positioning in Neonates over 32 Weeks of Gestational Age with Neonatal Respiratory Distress.

Respiratory distress (RD) is one of the most common causes of admission to the neonatal intensive care unit. Correct diagnosis and timely intervention are crucial. Lung ultrasonography (LU) is a useful diagnostic tool for the neonatologist in the diagnosis of RD; the neonatal lung ultrasonography score (nLUS) can be used in the diagnostic process, but some authors hypothesise that it is also useful for the management of some neonatal RD. The aim of this study is to analyse the changes in nLUS score before (T0) and after (T1) the start of respiratory support with nasal CPAP in neonates over 32 weeks of age with RD. Thirty-three newborns were enrolled in this retrospective study. LU was performed before and after the start of CPAP. The median nLUS scores at T0 and T1 were 9 (IQR 7−12) and 7 (IQR 4−10), respectively, and showed a significant difference (p < 0.001). The magnitude of reduction in nLUS score, expressed as a percentage, was inversely related to the need for subsequent administration of exogenous surfactant. The study suggests the usefulness of the nLUS score in assessing the response to CPAP in neonates over 32 weeks gestational age.

Early lung ultrasound score to predict noninvasive ventilation needing in neonates from 33 weeks of gestational age: A multicentric study.

OBJECTIVE: To propose an early lung ultrasound (LUS) score for the prediction of the need for respiratory assistance in newborns of gestational age (GA) ≥ 33 weeks presenting respiratory distress. STUDY DESIGN AND SETTING: Multicenter, prospective observational study in third-level neonatal intensive care units. PATIENT SELECTION: Infants with GA ≥ 33 + 0 weeks with respiratory distress within 3 h of life. METHODS: Three LUS for each patient were collected: within 3 h of life (T0), at 4-6 h of life (T1), and at the resolution of symptoms (T2). The primary aim was to assess the validity of the early LUS score in predicting the need for continuous positive airway pressure (CPAP). We also evaluated the validity of the score in predicting the need for surfactant, the scores' trend in our population, and any correlation with the duration of ventilation and oxygen therapy. RESULTS: Sixty-two patients were enrolled in the study. The mean GA was 36 weeks. The receiver operating characteristic analysis for the LUS T0 and T1 yielded area under the curves of 0.91 and 0.82 in predicting the need for CPAP, respectively. LUS score cut off of 6 (sensitivity 84.8%, specificity 86.2%) and 5 (sensitivity 66.7%, specificity 100%) were calculated at T0 and T1, respectively. We found significant correlations between LUS score and respiratory assistance, surfactant administration, and SpO2 /FiO2 ratio. CONCLUSION: An early LUS score is a good noninvasive predictor of the need for respiratory assistance with CPAP and surfactant administration in newborns with GA ≥ 33 weeks.

Presepsin levels in neonatal cord blood are not influenced by maternal SARS-CoV-2 infection.

OBJECTIVES: Coronavirus disease (COVID-19) can present with various symptoms and can involve multiple organs. Women infected during pregnancy have a higher incidence of obstetrical complications and infants born to "positive" mothers may get the infection with different manifestations. Presepsin seems to be a promising sepsis biomarker in adults and neonates. The aim of this study was to assess if presepsin levels in neonatal cord blood could be influenced by maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: A total of 119 neonates born from women with a confirmed diagnosis of SARS-CoV-2 infection were enrolled and presepsin levels of cord blood samples were collected. All neonates were tested for SARS-CoV-2 infection at birth and after 48-72 h. RESULTS: The median presepsin value in umbilical cord blood samples collected after birth was 455 pg/mL. Presepsin levels were not influenced by maternal symptoms of COVID-19, weight for gestational age, or delivery mode, and did not significantly differ between infants with and without adverse neonatal outcomes. Infants hospitalized for more than 5 days had a significantly higher presepsin level at birth rather than those discharged up to 4 days of life. Three infants with positive nasopharyngeal swab at birth had higher Presepsin levels than two infants tested positive at 48 h. CONCLUSIONS: This is the first study reporting cord presepsin levels in term and preterm infants born to mothers with COVID-19, that appeared to be not influenced by maternal clinical presentation. However, further studies are needed to explain the mechanisms of P-SEP increase in neonates exposed to perinatal maternal SARS-CoV-2 infection or with an indeterminate/possible SARS-CoV-2 infection in the same neonates.

Sulfonylurea-Insensitive Permanent Neonatal Diabetes Caused by a Severe Gain-of-Function Tyr330His Substitution in Kir6.2.

BACKGROUND/AIMS: Mutations in KCNJ11, the gene encoding the Kir6.2 subunit of pancreatic and neuronal KATP channels, are associated with a spectrum of neonatal diabetes diseases. METHODS: Variant screening was used to identify the cause of neonatal diabetes, and continuous glucose monitoring was used to assess effectiveness of sulfonylurea treatment. Electrophysiological analysis of variant KATP channel function was used to determine molecular basis. RESULTS: We identified a previously uncharacterized KCNJ11 mutation, c.988T>C [p.Tyr330His], in an Italian child diagnosed with sulfonylurea-resistant permanent neonatal diabetes and developmental delay (intermediate DEND). Functional analysis of recombinant KATP channels reveals that this mutation causes a drastic gain-of-function, due to a reduction in ATP inhibition. Further, we demonstrate that the Tyr330His substitution causes a significant decrease in sensitivity to the sulfonylurea, glibenclamide. CONCLUSIONS: In this subject, the KCNJ11 (c.988T>C) mutation provoked neonatal diabetes, with mild developmental delay, which was insensitive to correction by sulfonylurea therapy. This is explained by the molecular loss of sulfonylurea sensitivity conferred by the Tyr330His substitution and highlights the need for molecular analysis of such mutations.