MYCN in human development and diseases.

Somatic mutations in MYCN have been identified across various tumors, playing pivotal roles in tumorigenesis, tumor progression, and unfavorable prognoses. Despite its established notoriety as an oncogenic driver, there is a growing interest in exploring the involvement of MYCN in human development. While MYCN variants have traditionally been associated with Feingold syndrome type 1, recent discoveries highlight gain-of-function variants, specifically p.(Thr58Met) and p.(Pro60Leu), as the cause for megalencephaly-polydactyly syndrome. The elucidation of cellular and murine analytical data from both loss-of-function (Feingold syndrome model) and gain-of-function models (megalencephaly-polydactyly syndrome model) is significantly contributing to a comprehensive understanding of the physiological role of MYCN in human development and pathogenesis. This review discusses the MYCN's functional implications for human development by reviewing the clinical characteristics of these distinct syndromes, Feingold syndrome, and megalencephaly-polydactyly syndrome, providing valuable insights into the understanding of pathophysiological backgrounds of other syndromes associated with the MYCN pathway and the overall comprehension of MYCN's role in human development.

High Shear Stress Reduces ERG Causing Endothelial-Mesenchymal Transition and Pulmonary Arterial Hypertension.

Pathological high shear stress (HSS, 100 dyn/cm 2 ) is generated in distal pulmonary arteries (PA) (100-500 µm) in congenital heart defects and in progressive PA hypertension (PAH) with inward remodeling and luminal narrowing. Human PA endothelial cells (PAEC) were subjected to HSS versus physiologic laminar shear stress (LSS, 15 dyn/cm 2 ). Endothelial-mesenchymal transition (EndMT), a feature of PAH not previously attributed to HSS, was observed. H3K27ac peaks containing motifs for an ETS-family transcription factor (ERG) were reduced, as was ERG-Krüppel-like factors (KLF)2/4 interaction and ERG expression. Reducing ERG by siRNA in PAEC during LSS caused EndMT; transfection of ERG in PAEC under HSS prevented EndMT. An aorto-caval shunt was preformed in mice to induce HSS and progressive PAH. Elevated PA pressure, EndMT and vascular remodeling were reduced by an adeno-associated vector that selectively replenished ERG in PAEC. Agents maintaining ERG in PAEC should overcome the adverse effect of HSS on progressive PAH.

Furin Regulates the Alveolarization of Neonatal Lungs in a Mouse Model of Hyperoxic Lung Injury.

Despite advances in treatment options, such as corticosteroid administration and less invasive respiratory support, bronchopulmonary dysplasia (BPD) remains an important prognostic factor in preterm infants. We previously reported that furin regulates changes in lung smooth muscle cell phenotypes, suggesting that it plays a critical role in BPD pathogenesis. Therefore, in this study, we aimed to evaluate whether it regulates the alveolarization of immature lungs through activating alveolarization-driving proteins. We first examined furin expression levels, and its functions, using an established hyperoxia-induced BPD mouse model. Thereafter, we treated mice pups, as well as primary myofibroblast cell cultures, with furin inhibitors. Finally, we administered the hyperoxia-exposed mice pups with recombinant furin. Immunofluorescence revealed the co-expression of furin with alpha-smooth muscle actin. Hyperoxia exposure for 10 d decreased alveolar formation, as well as the expression of furin and its target, IGF-1R. Hexa-D-arginine administration also significantly inhibited alveolar formation. Another furin inhibitor, decanoyl-RVKR-chloromethylketone, accumulated pro-IGF-1R, and decreased IGF-1R phosphorylation in myofibroblast primary cultures. Finally, recombinant furin treatment significantly improved alveolarization in hyperoxia-exposed mice pups. Furin regulates alveolarization in immature lungs. Therefore, this study provides novel insights regarding the involvement of furin in BPD pathogenesis, and highlights a potential treatment target for ameliorating the impact of BPD.

Gain-of-function MYCN causes a megalencephaly-polydactyly syndrome manifesting mirror phenotypes of Feingold syndrome.

MYCN, a member of the MYC proto-oncogene family, regulates cell growth and proliferation. Somatic mutations of MYCN are identified in various tumors, and germline loss-of-function variants are responsible for Feingold syndrome, characterized by microcephaly. In contrast, one megalencephalic patient with a gain-of-function variant in MYCN, p.Thr58Met, has been reported, and additional patients and pathophysiological analysis are required to establish the disease entity. Herein, we report two unrelated megalencephalic patients with polydactyly harboring MYCN variants of p.Pro60Leu and Thr58Met, along with the analysis of gain-of-function and loss-of-function Mycn mouse models. Functional analyses for MYCN-Pro60Leu and MYCN-Thr58Met revealed decreased phosphorylation at Thr58, which reduced protein degradation mediated by FBXW7 ubiquitin ligase. The gain-of-function mouse model recapitulated the human phenotypes of megalencephaly and polydactyly, while brain analyses revealed excess proliferation of intermediate neural precursors during neurogenesis, which we determined to be the pathomechanism underlying megalencephaly. Interestingly, the kidney and female reproductive tract exhibited overt morphological anomalies, possibly as a result of excess proliferation during organogenesis. In conclusion, we confirm an MYCN gain-of-function-induced megalencephaly-polydactyly syndrome, which shows a mirror phenotype of Feingold syndrome, and reveal that MYCN plays a crucial proliferative role, not only in the context of tumorigenesis, but also organogenesis.

An infant with a heterozygous variant of ABCG5 presented with hypercholesterolemia only during breastfeeding.

Sitosterolemia (OMIM #210250) is a rare lipid disorder caused by variants in genes encoding adenosine triphosphate (ATP)-binding cassette subfamily G Member 5 (ABCG5) or 8 (ABCG8), which play roles in the intestinal and biliary excretion of cholesterol and plant sterols, such as sitosterol and campesterol. Although considered an autosomal recessive disorder, recent reports have shown that a heterozygous ABCG5 variant can also cause mild symptoms. Here, we report the case of an infant with a heterozygous variant of ABCG5. A 6-mo-old breast-fed Japanese male infant was found to have elevated serum total cholesterol and low-density lipoprotein-cholesterol (LDL-C) levels of 528 mg/dL and 449 mg/dL, respectively, upon examination for growth disturbances. As weaning progressed, the cholesterol levels normalized. Genetic analysis revealed that the patient and his mother had the heterozygous variant c.1166G>A (p.Arg389His) in ABCG5. Compared to his father, who did not have the ABCG5 variant, the patient and his mother had mild elevations of serum sitosterol and campesterol. Serum sitosterol and campesterol levels were 9.6 and 12 µg/mL for the patient, 4.9 and 9.3 µg/mL for his mother, and 2.1 and 3.4 µg/mL for his father, respectively. Therefore, heterozygous variants of ABCG5 may lead to transient hypercholesterolemia during breastfeeding.

Relationship between Birth Order and Postnatal Growth until 4 Years of Age: The Japan Environment and Children's Study.

Later-borns tend to be shorter than first-borns in childhood and adulthood. However, large-scale prospective studies examining growth during infancy according to birth order are limited. We aimed to investigate the relationship between birth order and growth during the first 4 years of life in a Japanese prospective birth cohort study. A total of 26,249 full-term singleton births were targeted. General linear and multivariable logistic regression models were performed and adjusted for birth weight, parents' heights, maternal age at delivery, gestational weight gain, maternal smoking and alcohol drinking status during pregnancy, household income, breastfeeding status, and Study Areas. The multivariate adjusted mean length Z-scores in "first-borns having no sibling", "first-borns having siblings", "second-borns", and "third-borns or more" were -0.026, -0.013, 0.136, and 0.120 at birth and -0.324, -0.330, -0.466, and -0.569 at 10 months, respectively. Results similar to those at 10 months were observed at 1.5, 3, and 4 years. The adjusted odds ratios (95% confidence intervals) of short stature at 4 years in "first-borns having siblings", "second-borns", and "third-borns or more" were 1.08 (0.84-1.39), 1.36 (1.13-1.62), and 1.50 (1.20-1.88), respectively, versus "first-borns having no sibling". Birth order was significantly associated with postnatal growth and may be a factor predisposing to short stature in early childhood.

Hematocolpos due to lower vaginal agenesis in an adolescent girl.

Background: Hematocolpos due to imperforate hymen is an important differential diagnosis of abdominal pain in early adolescent stage. However, hematocolpos due to lower vaginal agenesis must be considered because the management differs. Case Presentation: A healthy 11-year-old girl presented with a 2-day left lower abdominal pain history. Her breast development had begun, but she had not reached menarche. Computed tomography showed high absorptive value liquid filling the upper vaginal to uterine cavity, a pale highly absorptive fluid component suggestive of hemorrhagic ascites in the abdominal cavity on both sides of the uterus, and normal bilateral ovaries. Magnetic resonance imaging diagnosed hematocolpos due to lower vaginal agenesis. The blood clot was aspirated with a transabdominal ultrasound-guided transvaginal puncture. Conclusion: History-taking, imaging tests, and appropriate collaboration with obstetrician/gynecologist with awareness of secondary sexual characteristics were crucial in this case.

Two cases of transplant-acquired food allergy who developed resensitization after a negative oral food challenge.

BACKGROUND: Cases of food allergy after hematopoietic stem cell and solid organ transplantation in previously nonallergic transplant recipients were reported as transplant-acquired food allergy (TAFA), but information about its long-term outcome is still limited. A phenomenon where patients reacquire food allergy by resuming daily consumption after a negative oral food challenge has not yet been reported. CASE PRESENTATION: We report two cases of TAFA after liver transplantation and cord blood transplantation. In each case, the threshold of daily consumption to cause allergic symptoms decreased when a negative oral food challenge was obtained. CONCLUSIONS: Our cases show an importance of gastrointestinal tract as a route of food sensitization because thresholds that caused allergic reactions decreased during their resuming process. We need to be careful with possible resensitization once a negative substantial dose was confirmed.

Adverse pregnancy outcomes of cancer survivors and infectious disease in their infants: The Japan Environment and Children's Study.

Birth cohort studies examining pregnancy and infant outcomes among adolescent and young adult (AYA) cancer survivors have been limited. The present study examined whether AYA cancer affects pregnancy outcomes of survivors and infectious diseases in their infants up to 1 year of age. Pregnant women were recruited for the Japan Environment and Children's Study, a nationwide, large-scale, prospective cohort study. The present study included 103,060 pregnant women and collected questionnaire-based data during the first and second/third trimester, and at 1 month, 6 months and 1 year after delivery. Adverse pregnancy outcomes and infectious diseases in infants up to 1 year of age were compared between AYA cancer survivors and pregnant women without a history of cancer using binominal logistic regression analyses and a multiple imputation method. Of 99,816 participants (3,244 were missing), 1,102 (1.1%) had a cancer history, including 812 participants (0.8%) with a history of cervical cancer. Among cervical cancer survivors, the adjusted (a)ORs were as follows: 3.25 (95% CI, 2.31-4.57; q=0.00) for a preterm birth <34 weeks' gestation; 2.82 (95% CI, 2.31-3.44; q=0.00) for a preterm birth <37 weeks' gestation; and 1.67 (95% CI, 1.36-2.06; q=0.00) for premature rupture of the membrane. Among the other cancer survivors, the aOR for caesarean section was 1.43 (95% CI, 1.10-1.87; q=0.0). Furthermore, lower respiratory tract inflammation in 1-year-old infants born by vaginal delivery increased significantly in cases with a history of cervical cancer (aOR, 1.77; 95% CI, 1.33-2.36; q=0.00). The present study identified the risk of lower respiratory tract inflammation in 1-year-old infants born by vaginal delivery in cervical cancer survivors for the first time. In addition, the frequency of caesarean section increased in all cancer survivors. No risk of congenital anomalies or other infections were found in the total group of cancer survivors.

Clinical diversity and molecular mechanism of VPS35L-associated Ritscher-Schinzel syndrome.

PURPOSE: The Retriever subunit VPS35L is the third responsible gene for Ritscher-Schinzel syndrome (RSS) after WASHC5 and CCDC22. To date, only one pair of siblings have been reported and their condition was significantly more severe than typical RSS. This study aimed to understand the clinical spectrum and underlying molecular mechanism in VPS35L-associated RSS. METHODS: We report three new patients with biallelic VPS35L variants. Biochemical and cellular analyses were performed to elucidate disease aetiology. RESULTS: In addition to typical features of RSS, we confirmed hypercholesterolaemia, hypogammaglobulinaemia and intestinal lymphangiectasia as novel complications of VPS35L-associated RSS. The latter two complications as well as proteinuria have not been reported in patients with CCDC22 and WASHC5 variants. One patient showed a severe phenotype and the other two were milder. Cells established from patients with the milder phenotypes showed relatively higher VPS35L protein expression. Cellular analysis found VPS35L ablation decreased the cell surface level of lipoprotein receptor-related protein 1 and low-density lipoprotein receptor, resulting in reduced low-density lipoprotein cellular uptake. CONCLUSION: VPS35L-associated RSS is a distinct clinical entity with diverse phenotype and severity, with a possible molecular mechanism of hypercholesterolaemia. These findings provide new insight into the essential and distinctive role of Retriever in human development.

A nationwide survey of Schaaf-Yang syndrome in Japan.

Schaaf-Yang syndrome (SYS) is a congenital disorder characterized by developmental delay, autism spectrum disorder and congenital joint contractures. In this study, a nationwide epidemiological questionnaire-based survey of SYS in the Japanese population was conducted to establish patient numbers, clinical features and genetic information. In the primary survey, we investigated the number of SYS patients. In the secondary survey, we obtained and analyzed detailed clinical and genetic information of SYS patients. This survey collected information on 25 genetically-confirmed patients. The major clinical symptoms included neonatal hypotonia (96% of the patients), poor suck in infancy (82%), developmental delay (100%) and joint contractures (83%). Other main symptoms and findings included characteristic facial features (100%), small hands (92%), eye abnormalities (92%) and short stature (79%). Based on the information collected on activities of daily living, 71% of patients were unable to walk, while 67%, 71%, and 81% of patients required full assistance with eating, toileting and bathing, respectively. Regarding inheritability, the genetic analysis of 21 patients revealed that 14 (67%) carried de novo truncating variants in the melanoma antigen L2 (MAGEL2) gene and seven (33%) had inherited truncating variants from their fathers who were carriers. This survey revealed the clinical and genetic features in Japanese SYS patients. The majority of SYS patients required assistance in many aspects of daily living, and there were a certain number of carriers of the imprinting disorder.

Genetic and clinical landscape of childhood cerebellar hypoplasia and atrophy.

PURPOSE: Cerebellar hypoplasia and atrophy (CBHA) in children is an extremely heterogeneous group of disorders, but few comprehensive genetic studies have been reported. Comprehensive genetic analysis of CBHA patients may help differentiating atrophy and hypoplasia and potentially improve their prognostic aspects. METHODS: Patients with CBHA in 176 families were genetically examined using exome sequencing. Patients with disease-causing variants were clinically evaluated. RESULTS: Disease-causing variants were identified in 96 of the 176 families (54.5%). After excluding 6 families, 48 patients from 42 families were categorized as having syndromic associations with CBHA, whereas the remaining 51 patients from 48 families had isolated CBHA. In 51 patients, 26 aberrant genes were identified, of which, 20 (76.9%) caused disease in 1 family each. The most prevalent genes were CACNA1A, ITPR1, and KIF1A. Of the 26 aberrant genes, 21 and 1 were functionally annotated to atrophy and hypoplasia, respectively. CBHA+S was more clinically severe than CBHA-S. Notably, ARG1 and FOLR1 variants were identified in 2 families, leading to medical treatments. CONCLUSION: A wide genetic and clinical diversity of CBHA was revealed through exome sequencing in this cohort, which highlights the importance of comprehensive genetic analyses. Furthermore, molecular-based treatment was available for 2 families.

High Maternal Total Cholesterol Is Associated With No-Catch-up Growth in Full-Term SGA Infants: The Japan Environment and Children's Study.

Objectives: Infants born small for gestational age (SGA) with no catch-up growth (No-CU) are at high risk of intellectual and developmental disabilities. However, factors leading to No-CU among SGA infants are unclear. This study aimed to examine the association between maternal total cholesterol (TC) in mid-pregnancy and No-CU at 3 years among full-term SGA infants. Study Design: The Japan Environment and Children's Study (JECS) is a nationwide prospective birth cohort study. We extracted a total of 2,222 mothers and full-term SGA infants (length and/or weight <-2 standard deviation [SD]) without congenital abnormalities from the original JECS cohort comprising a total of 104,062 fetal records. According to the distribution of maternal TC in the entire cohort, participants were classified into nine groups per each fifth percentile with the 20th-79th percentiles (204-260 mg/dl) as the reference group. No-CU was defined by a Z-score of height at 3 years <-2 SD according to the growth standard charts for Japanese children. Multivariable-adjusted logistic regression models were carried out using multiple imputations. Additionally, a multiple-adjusted restricted cubic spline model was performed in the complete dataset. Results: A total of 362 (16.3%) children were No-CU at 3 years. After adjusting for the Z-score of birth weight, age of mother, smoking status, weight gain during pregnancy, breastfeeding and meal frequency at 2 years, and parents' heights, the odds ratio (95% confidence intervals) of No-CU was 2.95 (1.28-6.80) for children whose maternal TC levels were in the highest category (≥294 mg/dl), compared to the reference group. A multiple-adjusted restricted cubic spline model showed a non-linear trend of the significant association between high maternal TC and No-CU (p for linear trend = 0.05, p for quadratic trend <0.05). Conclusion: High maternal TC at mid-pregnancy was associated with No-CU among SGA infants. Such infants should be carefully followed up to introduce appropriate growth hormonal treatment. The findings may support previous animal experimental studies which indicated that maternal high-fat diet exposure induces impairment of growth and skeletal muscle development in the offspring. Future studies are required to elucidate the detailed mechanism.

Admission temperature of very low birth weight infants and outcomes at three years old.

The lower body temperature of preterm newborns at admission to neonatal intensive care units (NICUs) is inversely associated with their morbidities and mortalities before discharge. This retrospective cohort study aimed to determine whether admission rectal temperature in very low birth weight infants (VLBWIs) is independently associated with a composite outcome of death or moderate-to-severe neurodevelopmental impairments as defined by a performance developmental quotient of < 70 at three years of age. VLBWIs admitted to the NICU between April 2010 and March 2016 were assesed. Developmental assessment was completed in 216 newborns. Nine and two infants died before and after discharge, respectively. A higher admission temperature was associated with a lower incidence of death or moderate-to-severe neurodevelopmental impairments with adjustment for gestational age, sex, antenatal steroid use, Apgar score, severe intraventricular hemorrhage, and severe bronchopulmonary dysplasia (odds ratio [OR] 0.424; 95% confidence interval [CI] 0.250-0.717; p = 0.001). The admission temperature remained as an independent variable of adverse outcome at three years of age even when the study cohort was limited to surviving infants (OR 0.448; 95% CI 0.259-0.774; p = 0.004). Further studies are needed to assess whether avoiding low body temperature at admission results in better long-term neurodevelopmental outcomes in VLBWIs.

Association of Maternal Total Cholesterol With SGA or LGA Birth at Term: the Japan Environment and Children's Study.

CONTEXT: Maternal cholesterol is important for fetal development. Whether maternal serum total cholesterol (maternal TC) levels in midpregnancy are associated with small (SGA) or large (LGA) for gestational age independent of prepregnancy body mass index (BMI) and weight gain during pregnancy is inconclusive. OBJECTIVE: This work aimed to prospectively investigate the association between maternal TC in midpregnancy and SGA or LGA. METHODS: The Japan Environment and Children's Study is a nationwide prospective birth cohort study in Japan. Participants in this study included 37 449 nondiabetic, nonhypertensive mothers with singleton birth at term without congenital abnormalities. Birth weight for gestational age less than the 10th percentile and greater than or equal to the 90th percentile were respectively defined as SGA and LGA by the Japanese neonatal anthropometric charts. RESULTS: The mean gestational age at blood sampling was 22.7 ±â€…4.0 weeks. After adjustment for maternal age, sex of child, parity, weight gain during pregnancy, prepregnancy BMI, smoking, alcohol drinking, blood glucose levels, household income, and study areas, 1-SD decrement of maternal TC was linearly associated with SGA (odds ratio [OR]: 1.20; 95% CI, 1.15-1.25). In contrast, 1-SD increment of maternal TC was linearly associated with LGA (OR: 1.13; 95% CI, 1.09-1.16). Associations did not differ according to prepregnancy BMI and gestational weight gain (P for interaction > .20). CONCLUSION: Maternal TC levels in midpregnancy were associated with SGA or LGA in a Japanese cohort. It may help to predict SGA and LGA. Favorable maternal lipid profiles for fetal development must be explored.

Airway gas temperature within endotracheal tube can be monitored using rapid response thermometer.

Inappropriate preparation of respiratory gases is associated with serious complications during mechanical ventilation. To develop a temperature monitoring system of respiratory gases within the endotracheal tube, four newborn piglets were studied using an ultra-rapid-response thermometer attached to the closed endotracheal tube suction system. Respiratory gas temperatures were monitored at the mouth-corner level of the endotracheal tube using three thermocouples (Tairway, inserted into the endotracheal tube via the closed suction system; Ttube_centre and Ttube_wall, embedded within the endotracheal tube 0.5 mm and 1.6 mm from the tube wall, respectively). Univariate analysis showed that inspiratory Ttube_centre and inspiratory Ttube_wall were positively correlated with inspiratory Tairway (both p < 0.001). Multivariate analysis showed the dependence of inspiratory Tairway on inspiratory Ttube_centre and Ttube_wall and deflation of endotracheal tube cuff (p < 0.001, p = 0.001 and p = 0.046, respectively). Inspiratory gas temperature within the endotracheal tube can be monitored using a thermometer attached to the closed endotracheal tube suction system. Our system, with further validation, might help optimise respiratory gas humidification during mechanical ventilation.

Peripheral nerves are involved in hypomyelinating leukodystrophy-3 caused by a homozygous AIMP1 variant.

INTRODUCTION: Aminoacyl-tRNA synthetase-interacting multifunctional protein 1 (AIMP1) is a non-catalytic component of the multi-tRNA synthetase complex that catalyzes the ligation of amino acids to their correct tRNAs. Bi-allelic truncating variants in the AIMP1 gene have been associated with hypomyelinating leukodystrophy-3 (HLD3; MIM 260600), which is characterized by hypomyelination, microcephaly, seizures and decreased life expectancy. Although peripheral nerve involvement has been assumed for HLD3, no compelling evidence is available to date. CASE REPORT: The case was a first-born Filipino male. He showed profound developmental delay, failure to thrive, and spasticity in his limbs. At three months of age he developed refractory epilepsy. Serial magnetic resonance imaging (MRIs) showed profound myelination delay and progressive cerebral atrophy. He showed abnormal nerve conduction studies. Genetic testing revealed a homozygous pathogenic variant in the AIMP1 gene (NM_004757.3: c.115C > T: p.Gln39*). The parents were heterozygous for the same variant. CONCLUSION: Here, we report a patient with a homozygous nonsense AIMP1 variant showing peripheral neuropathy as well as HLD3. Our case suggests that AIMP1 plays a pivotal role in the peripheral nerve as well as the central nervous system.

A Novel α-Spectrin Pathogenic Variant in Trans to α-Spectrin LELY Causing Neonatal Jaundice With Hemolytic Anemia From Hereditary Pyropoikilocytosis Coexisting With Gilbert Syndrome.

Hereditary pyropoikilocytosis is a subtype of hereditary elliptocytosis because of biallelic mutations of SPTA1, SPTB, and EPB41. The authors present a proband with neonatal jaundice and hemolytic anemia, with poikilocytosis in the blood film. Targeted next-generation sequencing identified Q267del trans to the αLELY allele in SPTA1. In addition, the proband presented coexisting Gilbert syndrome as determined by homozygous mutation of UGT1A1. Investigation of 13 relatives and his sibling revealed that only his sibling showed the same phenotype and genotype as the proband. This is the first report of molecular confirmation of coexisting hereditary pyropoikilocytosis and Gilbert syndrome and a novel mutation in SPTA1.

Phosphorylated proteome analysis of a novel germline ABL1 mutation causing an autosomal dominant syndrome with ventricular septal defect.

BACKGROUND: A gain-of-function mutation in germline ABL1 causes a syndrome including congenital heart defects. However, the molecular mechanisms of this syndrome remain unknown. In this study, we found a novel ABL1 mutation in a Japanese family with ventricular septal defect, finger contracture, skin abnormalities and failure to thrive, and the molecular mechanisms of these phenotypes were investigated. METHODS AND RESULTS: Whole-exome sequencing on several family members revealed a novel mutation (c.1522A > C, p.I508L) in the tyrosine kinase domain of ABL1, and complete co-segregation with clinical presentations was confirmed in all members. Wild-type and mutant ABL1 were transfected into human embryonic kidney 293 cells for functional analysis. Western blotting confirmed that tyrosine phosphorylation in STAT5, a substrate of ABL1, was enhanced, and the novel mutation was proved to be a gain-of-function mutation. Since this novel mutation in ABL1 enhances tyrosine kinase activity, phosphorylated proteome analysis was used to elucidate the molecular pathology. The proteome analysis showed that phosphorylation in proteins such as UFD1, AXIN1, ATRX, which may be involved in the phenotypes, was enhanced in the mutant group. CONCLUSIONS: The onset of congenital heart defects associated with this syndrome appears to involve a mechanism caused by UFD1 common to 22q.11.2 deletion syndrome. On the other hand, AXIN1 and ATRX may be important in elucidating the mechanisms of other phenotypes, such as finger contracture and failure to thrive. Verification of these hypotheses would lead to further understanding of the pathophysiology and the development of treatment methods.