[GENETIC PANELS FOR THE DIAGNOSIS OF RARE CONGENITAL HEMATOLOGICAL DISORDERS].

INTRODUCTION: Genetic diagnosis of congenital hematological disorders is complicated by the overlap of the clinical and laboratory presentation across different diseases and the large number of genes involved in each syndrome. Nonetheless, an accurate genetic diagnosis is essential for directing the follow-up and treatment program of the patients, as well as for identifying asymptomatic family members, choosing a non-affected related donor for hematopoietic stem cell transplantation and for offering a prenatal diagnosis. In recent years, a novel method of targeted next generation sequencing using gene panels was developed. In our laboratory, gene panels were incorporated for the diagnosis of congenital hematological disorders, including inherited bone marrow failure syndromes and rare anemias, and for the detection of somatic variant in the bone marrow. It is of utmost importance that an in-depth analysis will include a correlation of the genetic variants with the clinical and laboratory presentation and with the family history. Here, we demonstrate the importance of performing a timely genetic diagnosis in patients with congenital hematological disorders.

Discrepancia entre SpO2 y SaO2: diagnóstico de cuatro generaciones / From SpO2 and SaO2 discrepancy to diagnosing four generations

Pulse oximetry measures the peripheral oxy-haemoglobin saturation (SpO2) which is a surrogate marker for arterial oxy-haemoglobin saturation (SaO2). SaO2 estimation is subjected to both oximeter proper functioning, patient characteristicsand haemoglobin disturbances. A 82-year-old man goes to the emergency with cough, dyspnoea and fever. He has haemolytic anaemia. His kids also have anaemia. Examination showed fine crackles in pulmonary auscultation of the lower two thirds of the right lung and splenomegaly. SpO2 was 80% (FiO2 21%). Arterial blood gas analysis: pH 7.514; PaCO2 23.4 mmHg; PaO2 43.2 mmHg; Hb 13.0 g/dL. Chest X-ray suggested an infectious process. He was admitted to the hospital with the diagnosis of pneumonia. During hospitalization we verify discrepancy between SpO2 and SaO2; haemolytic anaemia. The patient had a respiratory improvement and was discharged to external consult, dying months later. To clarify the discrepancy between SpO2 and SaO2 results; confirm the hereditary nature and identify the haemolytic anaemia, we conducted a retrospective familiar study based on the patient’s clinical processes. Three children were identified with anaemia. Two of the children have known their anaemia for 35 years - studied in the context of respiratory infections with haemolytic crisis due to Lepore haemoglobinopathy and β thalassemia, respectively. The patient previously diagnosed with Lepore haemoglobinopathy, currently undergoing hospital anaemia study, was diagnosed with Köln Hb. The discrepancy between SpO2 and SaO2 in association with a familiar haemolytic anaemia resulted in the diagnosis of autosomal dominant Köln haemoglobinopathy. The advances in the means of diagnosis enabled the probable diagnosis of 19 family members distributed over 4 generations. (AU)

Impact of Next-Generation Sequencing on the Diagnosis and Treatment of Congenital Anemias.

Congenital anemias are a wide spectrum of diseases including hypoproliferative anemia syndromes, dyserythropoietic anemias, sideroblastic anemias, red blood cell membrane and enzymatic defects, hemoglobinopathies, and thalassemia syndromes. The various congenital anemia syndromes may have similar clinical and laboratory presentations, making the diagnosis challenging. The traditional work-up, which includes a complete blood count, blood smears, bone marrow studies, flow cytometry, and the osmotic fragility test, does not always lead to the diagnosis. Specialized tests such as red blood cell enzyme activity and ektacytometry are not widely available. In addition, red blood cell transfusions may mask some of the laboratory characteristics. Therefore, genetic testing is crucial for accurate diagnosis of patients with congenital anemias. However, gene-by-gene testing is labor intensive because of the large number of genes involved. Thus, targeted next-generation sequencing using custom-made gene panels has been increasingly utilized, with a high success rate of diagnosis. Accurate genetic diagnosis is important for determining specific therapeutic modalities, as well as for avoiding splenectomy when contraindicated. In addition, molecular diagnosis can allow for genetic counseling and prenatal diagnosis in severe cases. We suggest a work-up scheme for patients with congenital anemias, including early incorporation of targeted next-generation sequencing panels.

Congenital dyserythropoiesis anemia type Ia with a novel CDAN1 mutation diagnosed by whole exome sequencing.

BACKGROUND: Congenital dyserythropoiesis anemia type Ia (OMIM:224120), is a rare hereditary anemia. The diagnosis is difficult to make and usually delayed in part due to its rarity and nonspecific clinical manifestations. METHODS: Whole exome sequencing was applied for the genetic diagnosis of a 12-year-old boy who has suffered from hemolytic anemia since birth and who requires regular transfusions. Sanger sequencing of the variants detected in whole exome sequencing was performed in the patient and his parents. RESULTS: Compound heterozygous mutations of CDAN1 gene, including one previously reported and one novel mutation, which is a splicing change, were detected in the whole exome sequencing and confirmed by Sanger sequencing. The autosomal recessive inheritance was confirmed by pedigree analysis. CONCLUSION: To our knowledge, this is the first case report of congenital dyserythropoiesis anemia type Ia with genetic diagnosis to be located in Taiwan. Because of the rarity of CDA Ia and the overlapping of the clinical manifestations with other hereditary anemias, the next-generation sequencing approach is effective for conclusive diagnosis of CDA Ia.

Pregnancy outcomes amongst multiple sclerosis females with third trimester natalizumab use.

BACKGROUND: Natalizumab, a monoclonal antibody directed against alpha-4-integrin, is an efficacious treatment used in Multiple Sclerosis (MS). Use in early pregnancy is safe but information in the third trimester is limited. Ceasing natalizumab is often associated with an increased risk in MS relapse and in some instances natalizumab continuation during pregnancy may be required. However natalizumab crosses the placenta in late pregnancy and has been associated with hematological abnormalities. We present clinical and hematological outcome data of newborns from a series of MS patients who received natalizumab during their second and third pregnancy trimesters. We describe possible methods to mitigate risks to the fetus. METHODS: Retrospective chart review of 15 births from mothers receiving natalizumab throughout pregnancy. RESULTS: Thirteen mothers with third-trimester exposure to natalizumab were identified. Median age at conception was 34 years (26-40) and median disease duration was 53.5 months (11-204). The 13 mothers gave birth to 15 newborns (2 mothers each with 2 individual births), median (SD) birth weight was 2778 gs (2100 - 3790). Congenital or laboratory abnormalities were identified in 5 which included anemia (n = 2) and thrombocytopenia (n = 3). CONCLUSIONS: Complications following natalizumab administration during the second and third trimester of pregnancy occurred in 33% of newborns. However, did not result in mortality or morbidity. Dose alterations during the third trimester, pre-delivery umbilical cord sampling and IVIG administration may reduce hematological effects on newborns. Prospective studies with larger numbers of patients are required to provide further evidence regarding the safety of Natalizumab use in pregnancy.

Nonimmune Anemias.

Anemia in the newborn period can be a diagnostic challenge. This article explores the diagnosis, work-up, and differential diagnosis of anemia in this patient population with a focus on anemia that is not related to blood loss or immune-mediated conditions (isoimmune hemolysis).

Study of pathophysiology and molecular characterization of congenital anemia in India using targeted next-generation sequencing approach.

Most patients with anemia are diagnosed through clinical phenotype and basic laboratory testing. Nonetheless, in cases of rare congenital anemias, some patients remain undiagnosed despite undergoing an exhaustive workup. Genetic testing is complicated by the large number of genes that are involved in rare anemias, due to similarities in the clinical presentation. We sought to enhance the diagnosis of patients with congenital anemias by using targeted next-generation sequencing. The genetic diagnosis was performed by gene capture followed by next-generation sequencing of 76 genes known to cause anemia syndromes. Genetic diagnosis was achieved in 17 of 21 transfusion-dependent patients and undiagnosed by conventional workup. Four cases were diagnosed with red cell membrane protein defects, four patients were diagnosed with pyruvate kinase deficiency, one case of adenylate kinase deficiency, one case of glucose phosphate isomerase deficiency, one case of hereditary xerocytosis, three cases having combined membrane and enzyme defect, two cases with Diamond-Blackfan anemia (DBA) and 1 with CDA type II with 26 different mutations, of which 21 are novel. Earlier incorporation of this NGS method into the workup of patients with congenital anemia may improve patient care and enable genetic counselling.

Effects and safety of delayed versus early umbilical cord clamping in newborns of HIV-infected mothers.

OBJECTIVE: To investigate the effect of a 2 minutes-delayed cord clamp (DCC) versus early cord clamp (ECC) on neonate haemoglobin concentration 24 hours and 1 month after birth, and assess the safety of DCC concerning the risk of HIV infection. DESIGN: Sixty-four mother-infant peers were enrolled. All mothers were on stable ARV therapy. Viral load, CD4+ count and blood haemoglobin (Hb) concentrations 24 hours before delivery were collected from all mothers and their infants. METHODS: All patients were enrolled at the Department of Paediatrics, AO FBF Sacco Hospital in Milan, and were followed until 18 months after birth. Women with haematological diseases and obstetrical complications were excluded. All of 64 mother and infants couples (32 ECC group and 32 DCC group) completed the study. ECC and DCC are defined as application of umbilical clamp within 30 seconds and 120 seconds after birth, respectively. RESULTS: Mean birth weight was significantly higher in the DCC compared with ECC group. Mean Hb levels at birth were significantly higher in DCC than in ECC group (p = .05): this difference persisted at 1 month of life. All newborns showed negative viral load. CONCLUSIONS: DCC 2 minutes after birth is proven to be a safe procedure, particularly beneficial in newborns from HIV mothers. The risk of anemia is significantly decreased at 24 hours after birth and persists at age of 1 month without any increased risk of neonatal jaundice or polycitemia.

Improved prediction of twin anemia-polycythemia sequence by delta middle cerebral artery peak systolic velocity: new antenatal classification system.

OBJECTIVES: To investigate the diagnostic accuracy of delta middle cerebral artery peak systolic velocity (MCA-PSV) > 0.5 multiples of the median (MoM) and compare its predictive value with that of the current MCA-PSV cut-off values of > 1.5 MoM in the donor and < 1.0 MoM in the recipient, for the diagnosis of twin anemia-polycythemia sequence (TAPS) in monochorionic twin pregnancy. METHODS: This was a retrospective consecutive cohort study comprising all uncomplicated monochorionic twin pregnancies and twin pregnancies with a postnatal diagnosis of TAPS managed between 2003 and 2017 in the Dutch national referral center for fetal therapy. Cases with incomplete MCA-PSV Doppler measurements 1 week prior to delivery or with incomplete hemoglobin measurements within 1 day after birth were excluded. The postnatal diagnosis of TAPS was based on an intertwin hemoglobin difference > 8 g/dL and at least one of the following: reticulocyte count ratio > 1.7 or presence of minuscule anastomoses on the placental surface. We compared the predictive accuracy of the current diagnostic method using MCA-PSV cut-off values of > 1.5 MoM in the donor and < 1.0 MoM in the recipient with that of a new method based on intertwin difference in MCA-PSV > 0.5 MoM for prediction of TAPS. RESULTS: In total, 45 uncomplicated and 35 TAPS monochorionic twin pregnancies were analyzed. The sensitivity and specificity of the cut-off MCA-PSV values (donor > 1.5 MoM, recipient < 1.0 MoM) to predict TAPS was 46% (95% CI, 30-62%) and 100% (95% CI, 92-100%), respectively; positive predictive value was 100% (95% CI, 81-100%) and negative predictive value 70% (95% CI, 58-80%). Delta MCA-PSV showed a sensitivity of 83% (95% CI, 67-92%) and a specificity of 100% (95% CI, 92-100%); the positive and negative predictive values were 100% (95% CI, 88-100%) and 88% (95% CI, 77-94%), respectively. Of the 35 cases with TAPS diagnosed postnatally, 13 twin pairs showed a delta MCA-PSV > 0.5 MoM but did not fulfill the cut-off MCA-PSV criteria. Of these 13 TAPS twins, nine donors and four recipients had normal MCA-PSV values. There was a high correlation between delta MCA-PSV and intertwin difference in hemoglobin level (R = 0.725, P < 0.01). CONCLUSION: Delta MCA-PSV > 0.5 MoM has a greater diagnostic accuracy for predicting TAPS compared to the current MCA-PSV cut-off criteria. We therefore propose a new antenatal classification system for TAPS. In monochorionic twin pregnancies with delta MCA-PSV > 0.5 MoM on Doppler ultrasound, but normal MCA-PSV values in the donor or recipient, obstetricians should be aware of the therapeutic implications and neonatal morbidities associated with TAPS. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Role of fetal intertwin difference in middle cerebral artery peak systolic velocity in predicting neonatal twin anemia-polycythemia sequence.

OBJECTIVES: To evaluate the relationship between the fetal intertwin difference in middle cerebral artery peak systolic velocity (MCA-PSV) and intertwin difference in hemoglobin (Hb) concentration at birth in monochorionic diamniotic (MCDA) twin pregnancies in order to assess its potential role in the prediction of twin anemia-polycythemia sequence (TAPS). METHODS: This was a retrospective cohort study of MCDA twin pregnancies delivered between January 2012 and January 2018. All pregnancies with measurements of MCA-PSV within 7 days prior to delivery and in which neonatal Hb concentration was available were included. The correlation between fetal intertwin difference in MCA-PSV, expressed in multiples of the median (MoM), and neonatal intertwin difference in Hb concentration was investigated. Receiver-operating characteristics (ROC) curve analysis was used to assess the performance of fetal intertwin difference in MCA-PSV for predicting intertwin difference in Hb > 90th centile at birth. RESULTS: A total of 154 out of 256 MC twin pregnancies fulfilled the inclusion criteria. Fetal intertwin difference in MCA-PSV MoM correlated positively with neonatal intertwin difference in Hb concentration (r = 0.79; P < 0.001). The 90th centile for intertwin difference in Hb was 7.25 g/dL. There were 15 (9.7%) cases with a Hb difference ≥ 7.25 g/dL at birth. ROC curve analysis showed a high accuracy of fetal intertwin MCA-PSV MoM difference for the prediction of neonatal intertwin Hb difference ≥ 7.25 g/dL at birth (area under the ROC curve, 0.976 (95% CI, 0.935-0.993); P = 0.012). The optimal cut-off for intertwin MCA-PSV MoM difference was 0.373, with a sensitivity of 93.3% (95% CI, 68.1-99.8%) and a specificity of 95.7% (95% CI, 90.8-98.4%). The positive predictive value was 70% (95% CI, 45.7-88.1%) and the negative predictive value was 99.3% (95% CI, 95.9-100%). CONCLUSION: Our findings show that fetal intertwin MCA-PSV MoM difference is a good predictor of neonatal intertwin Hb concentration difference > 90th centile and potentially of TAPS. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Targeted next generation sequencing for the diagnosis of patients with rare congenital anemias.

BACKGROUND: Most patients with anemia are diagnosed through clinical phenotype and basic laboratory testing. Nonetheless, in cases of rare congenital anemias, some patients remain undiagnosed despite undergoing an exhaustive workup. Genetic testing is complicated by the large number of genes involved in rare anemias and the similarities in the clinical presentation of the different syndromes. OBJECTIVE: We aimed to enhance the diagnosis of patients with congenital anemias by using targeted next-generation sequencing. METHODS: Genetic diagnosis was performed by gene capture followed by next-generation sequencing of 76 genes known to cause anemia syndromes. RESULTS: Genetic diagnosis was achieved in 13 out of 21 patients (62%). Six patients were diagnosed with pyruvate kinase deficiency, 4 with dehydrated hereditary stomatocytosis, 2 with sideroblastic anemia, and 1 with CDA type IV. Eight novel mutations were found. In 7 patients, the genetic diagnosis differed from the pretest presumed diagnosis. The mean lag time from presentation to diagnosis was over 13 years. CONCLUSIONS: Targeted next-generation sequencing led to an accurate diagnosis in over 60% of patients with rare anemias. These patients do not need further diagnostic workup. Earlier incorporation of this method into the workup of patients with congenital anemia may improve patients' care and enable genetic counseling.

[Intrauterine blood transfusion: Status report of 4years of practice in France (2011-2014)]. / Transfusions fœtales érythrocytaires : état des lieux sur 4 ans en France (2011­2014).

OBJECTIVES: The aim of our study was to evaluate in utero blood transfusion's (IUT) performed in France, among the French prenatal diagnosis centers in order to study the etiology of severe anemia requiring IUT. METHODS: We conducted a national retrospective descriptive study between 2011 and 2014. The data were collected using a survey sent by email to all French prenatal diagnosis centers. RESULTS: Among the 49 centers, 18 (38 %) had performed at least one IUT during the study period. The geographical repartition of these centers was appropriate for the "Aquitaine Pyrénées" region. Five centers performed 68 % of the national activity and one center performed 40 % the national activity. Each year, a mean of 204 IUTs were performed in 113 pregnancies. The principal etiology of severe fetal anemia requiring IUT was hemolytic disease of the fetus (69 % of the etiologies) with anti-RhD being the most prevalent antibody. The second etiology was represented by parvovirus B19 infection (17 % of IUTs). CONCLUSION: The French IUT activity was stable in numbers and indications during the study period. A national register could be set up in order to better evaluate prospectively the number of pregnancies concerned by IUT and to study the prevalence of hemolytic disease of the fetus due to anti-RhD antibodies.

Novel NLRC4 Mutation Causes a Syndrome of Perinatal Autoinflammation With Hemophagocytic Lymphohistiocytosis, Hepatosplenomegaly, Fetal Thrombotic Vasculopathy, and Congenital Anemia and Ascites.

Autoinflammatory diseases are caused by pathologic activation of the innate immune system. Primary hemophagocytic lymphohistiocytosis (HLH) is an aggressive syndrome of excessive immune activation caused by monogenic mutations resulting in cytotoxic cell defects and subsequent failure to eliminate activated macrophages. Secondary HLH is often diagnosed in cases without a known Mendelian inheritance. However, some cases of "secondary" HLH have been shown to harbor mutations with partial dysfunction of the cytotoxic system. Recently, macrophage intrinsic abnormalities caused by NLRC4 inflammasome mutations have been linked to autoinflammation and recurrent macrophage activation syndromes resembling a primary HLH. We report a case of a former 28-week preterm infant with congenital anemia, ascites, and a heavy edematous placenta with fetal thrombotic vasculopathy, who developed hepatosplenomegaly and unexplained systemic inflammation with laboratory features of HLH in the early postnatal course and died at 2 months of age. Postmortem examination confirmed the hepatosplenomegaly with marked sinusoidal hemophagocytosis, along with striking hemophagocytosis in the bone marrow and lymph nodes. There was extensive acute and chronic ischemic bowel disease with matted bowel loops, fibrous adhesions, and patchy necrotizing enterocolitis features. Whole exome sequencing analysis demonstrated a novel mosaic heterozygous NLRC4 512 C> T (p.Ser171Phe) de novo mutation predicated to cause a dominant, gain-of-function mutation resulting in a constitutively active protein. The assembly of NLRC4-containing inflammasomes via an induced self-propagation mechanism likely enables a perpetuating process of systemic macrophage activation, presumed to be initiated in utero in this patient.

Emerging cellular and gene therapies for congenital anemias.

Congenital anemias comprise a group of blood disorders characterized by a reduction in the number of peripherally circulating erythrocytes. Various genetic etiologies have been identified that affect diverse aspects of erythroid physiology and broadly fall into two main categories: impaired production or increased destruction of mature erythrocytes. Current therapies are largely focused on symptomatic treatment and are often based on transfusion of donor-derived erythrocytes and management of complications. Hematopoietic stem cell transplantation represents the only curative option currently available for the majority of congenital anemias. Recent advances in gene therapy and genome editing hold promise for the development of additional curative strategies for these blood disorders. The relative ease of access to the hematopoietic stem cell compartment, as well as the possibility of genetic manipulation ex vivo and subsequent transplantation in an autologous manner, make blood disorders among the most amenable to cellular therapies. Here we review cell-based and gene therapy approaches, and discuss the limitations and prospects of emerging avenues, including genome editing tools and the use of pluripotent stem cells, for the treatment of congenital forms of anemia. © 2016 Wiley Periodicals, Inc.

Prevalence of anemia and associations between neonatal iron status, hepcidin, and maternal iron status among neonates born to pregnant adolescents.

BACKGROUND: Little is known about anemia and iron status in US newborns because screening for anemia is typically not undertaken until 1 y of age. This study was undertaken to characterize and identify determinants of iron status in newborns born to pregnant adolescents. METHODS: Pregnant adolescents (≤ 18 y, n = 193) were followed from ≥ 12 wk gestation until delivery. Hemoglobin, ferritin, soluble transferrin receptor, serum iron, hepcidin, erythropoietin (EPO), IL-6, and C-reactive protein were assessed in maternal and cord blood. RESULTS: At birth, 21% of the neonates were anemic (Hb < 13.0 g/dl) and 25% had low iron stores (ferritin < 76 µg/l). Cord serum ferritin concentrations were not significantly associated with gestational age (GA) at birth across the range of 37-42 wk. Neonates born to mothers with ferritin < 12 µg/l had significantly lower ferritin (P = 0.003) compared to their counterparts. Hepcidin and IL-6 were significantly (P < 0.05) higher in neonates born to mothers with longer durations of active labor. CONCLUSION: Given the importance of the iron stores at birth on maintenance of iron homeostasis over early infancy, additional screening of iron status at birth is warranted among those born to this high risk obstetric population.