Caucasian Boy Research Articles

P16 Hypopigmented Mycosis Fungoides in a Caucasian child

Abstract We report a case of hypopigmented MF in an 8-year-old Caucasian boy whose skin had been managed as pityriasis alba for a number of years. On initial presentation to the emergency department, multiple non-itchy scattered hypopigmented macules were incidentally noted on the lower abdomen, groin, lateral flanks and axillae. Physical examination revealed widespread hypopigmented patches. Differential diagnoses included pityriasis alba or post inflammatory hypopigmentation secondary to atopic dermatitis. He was initially managed with mild to moderate corticosteroids and emollients, but continued to develop multiple atypical asymmetrical macules, particularly on the lower abdomen and groin. Although the skin was responsive to anti-inflammatory treatment, given the progression, a skin biopsy was requested. A lesional punch biopsy from the abdomen revealed focal lymphocyte exocytosis and interface change at the epidermis. Given the subtle findings the case was discussed at our histopathology MDT meeting. Further specialist review of the histopathology showed clinicopathological correlation in keeping with CD8+ mycosis fungoides (hypopigmented variant). He is currently managed with regular potent topical steroids, 0.1% topical tacrolimus. TL01 phototherapy has been suggested. Juvenile onset MF constitutes hypopigmented, poikilodermatosis, pityriasis lichenoides-like, folliculotropic, and pigmented purpura- like presentations1. Generally there is no disease progression beyond stage 1A or 1B disease2. Hypopigmented MF is well described in black and Asian skin types but it is also important to appreciate that multiple reoccurring atypical hypopigmented patches in Caucasian skin may also be a variant of hypopigmented MF.

Fever of Unknown Origin in Children: The Challenge of History Taking

A fever of unknown origin (FUO) in children is usually described as a fever of at least 8 days duration with no apparent diagnosis after initial investigations, including taking medical history and preliminary laboratory assessment. Infectious diseases are the most common cause of FUO, followed by rheumatologic and neoplastic conditions. In this report, we present a case of a 15-year-old Caucasian boy with a silent past medical history, who presented at our Pediatric ER department with a three-day history of fever, fatigue, and abdominal pain with diarrhoea. Initial laboratory testing and microbiological work-up were non-significant. At hospital admission, a broad infectious diagnostic work-up was pursued, including serologies and polymerase-chain-reaction (PCR) for CMV, EBV, HAV, Parvovirus, Toxoplasma gondii and Adenovirus, all negative. Given mild splenomegaly and linfadenopathy, systemic Juvenile Idiopathic Arthritis (s-JIA) was suspected, as well as Multi-inflammatory Syndrome in Children (MIS-C), but the patient did not meet their main diagnostic criteria. Malignancy was ruled out by a negative bone marrow fine-needle aspiration cytology and whole-body PET-CT scan. On hospital day 8, Brucella was identified on a new set of blood cultures and a combined antibiotic therapy was started with IV Gentamicin plus per os Doxycycline. The patient’s general conditions rapidly improved, and both fever and diarrhoea resolved. A reassessment of the patient’s medical history before discharge revealed exposure to unpasteurized soft cheese in the weeks prior to the onset of symptoms. This case underlines the importance of taking a complete medical history, as well as a full diagnostic work-up to unveil unusual infectious etiologies behind FUO. After the preliminary negative microbiological tests, a connective tissue disease was ruled out (i.e. lack of cutaneous or articular involvement), as well as malignancy, which led to a closer evaluation for infection and the diagnosis of Brucellosis.

Inflammatory dilated cardiomyopathy associated with psoriasis: a case report

BackgroundPsoriasis is a chronic inflammatory skin disease with a genetic basis. Psoriasis is accepted as a systemic, immune-mediated disease. Hypertension, obesity, metabolic disorders including diabetes mellitus and hyperlipidemia, and psychiatric disorders are more prevalent among children with psoriasis compared to children without psoriasis. In this study, we report a case of dramatic response of inflammatory cardiomyopathy to anti-inflammatory treatment of psoriasis; which might reveal similar pathogenesis basis of these two diseases.Case presentationA 9-year-old Caucasian boy presenting with signs and symptoms of heart failure refractory to conventional therapies was admitted to our pediatric cardiology service. As the patient also had psoriasis, and considering the fact that there might be an association between the two conditions, immunosuppressive drugs were administered, which led to a dramatic improvement in heart function.ConclusionsThe results of this study add to evidence linking psoriasis with inflammatory dilated cardiomyopathy. Clinicians, particularly cardiologists, must pay special attention to the cardiac complications of systemic diseases.

Severe lympho-depletion, abrogated thymopoiesis and systemic EBV positive T-cell lymphoma of childhood, a case

Epstein-Barr virus (EBV) associated T-cell and NK-cell lymphoproliferative diseases are lethal and extremely rare in Caucasians. We expand on the clinical, immunological and histogenetic characteristics associated with this second European case (19 years old, previously healthy, Caucasian boy) of systemic EBV positive T-cell lymphoma of childhood. We report, as novel findings, severe lympho-depletion and abrogation of thymopoiesis secondary to severe EBV activation and excessive immune activation. Similar to the first European case, we also detected a somatic missense variant in the proto-oncogene FYN. In the first European patient however, the FYN variant allele frequency (VAF) was 10% and the patient only experienced moderate leukopenia, whereas in our case, the VAF was 48% and the patient experienced severe leukopenia and lymphopenia. This could suggest a pathogenic role of these FYN variants in driving excessive T cell activation. If confirmed, FYN might become target in future treatments of this fatal disorder.

Reconstruction of isolated hypoplasia of the patella by a modified Galeazzi procedure: a case report

BackgroundIsolated Patellar Aplasia Hypoplasia is a very rare autosomal dominant disorder. Its treatment depends on the clinical manifestations that can vary widely. The lack of active extension, which can be responsible for frequent falls due to a knee instability, is the most frequent and disabling manifestation. We report an original technique that is a modification of the Galeazzi technique for recurrent dislocation of the patella to gain active extension in case of PTLAH.Case reportA 7-year-old Caucasian boy with isolated Patellar Aplasia Hypoplasia and an extension lag of the right knee has been treated by a modified Galeazzi technique. The tendons of the semi-tendinous and gracilis muscles have been harvested and their distal insertion was kept intact. Both tendons were fixed over the top of the patella to restore knee active extension. After 6 years of follow up the patient is symptom free with a strong active extension of the operated knee.ConclusionReconstruction of isolated hypoplasia of the patella by a modified Galeazzi procedure is a safe and reliable technique for skeletally immature patients offering satisfying long-term outcomes.

Wolman disease presenting with hemophagocytic lymphohistiocytosis syndrome and a novel LIPA gene variant: a case report and review of the literature

BackgroundWolman disease is a rare disease caused by the absence of functional liposomal acid lipase due to mutations in LIPA gene. It presents with organomegaly, malabsorption, and adrenal calcifications. The presentations can resemble hemophagocytic lymphohistiocytosis, the life threatening hyperinflammatory disorder. Since the disease is very rare, clinicians might not think of it when a patient presents with hemophagocytic lymphohistiocytosis, and the opportunity to treat it properly can be lost, thus leading to demise of the child.Case presentationWe present a 4.5-month-old Caucasian boy with fever, icterus, and hepatosplenomegaly who was treated according to presumed hemophagocytic lymphohistiocytosis disease. Wolman disease was diagnosed after the death of the child. There are some case reports in the literature presenting patients with Wolman disease primarily diagnosed as hemophagocytic lymphohistiocytosis, which we discuss in this review. The genetic analysis revealed after his demise was compatible with Wolman disease, introducing a novel mutation in LIPA gene: exon 4: NM_001127605: c. G353A (p.G118D), which converts the glycine amino acid to aspartic acid.ConclusionsConsidering the similarities in presentation of Wolman disease and hemophagocytic lymphohistiocytosis, the patient’s life can be saved if special attention is paid to presenting features of a patient with suspected hemophagocytic lymphohistiocytosis, that is special attention to symptoms, findings on physical exams, laboratory values, and radiologic findings, and the proper treatment is urgently initiated. Reporting the novel mutations of Wolman disease can help geneticists interpret the results of their patients’ genetic studies appropriately, leading to correct diagnosis and treatment.

KIRREL3-related disorders: a case report confirming the radiological features and expanding the clinical spectrum to a less severe phenotype

BackgroundNeurodevelopmental disorders have a multifactorial etiology, since biological, genetic, psychosocial and environmental risk factors are involved. Recent studies have been linking neurodevelopmental disorders and intellectual disability with a variety of genes, some of which encoding neuronal cell-adhesion molecules. Among these, KIRREL3 is known to play a role in CNS development, and his variants have recently been related to intellectual disability, autism spectrum disorder, childhood apraxia of speech, cerebellar hypoplasia and mild dysmorphic features.Case presentationIn this study, we describe a young Caucasian boy with mild intellectual disability, cerebellar anomalies (cerebellar hypoplasia and mega cisterna magna) and minor dysmorphic features associated to a novel KIRREL3 variant.ConclusionsAim of the present case report is to expand the clinical spectrum of KIRREL3-related diseases towards a milder phenotype than what is already described in the literature. We speculate that the interaction between KIRREL3 and CASK might play a major role in promoting cognitive and cerebellar development, contributing to a variety of clinical manifestations.

Anti-N-methyl-d-aspartate receptor encephalitis and positive human herpesvirus-7 deoxyribonucleic acid in cerebrospinal fluid: a case report

BackgroundAnti-N-methyl-d-aspartate receptor encephalitis is a neuroautoimmune syndrome typically presenting with seizures, psychiatric symptoms, and autonomic dysfunction. Human herpesvirus-7 is often found with human herpesvirus-6 and infects leukocytes such as T-cells, monocytes–macrophages, epithelial cells, and central nervous system cells. The pathogenicity of human herpesvirus-7 is unclear. Cases of anti-N-methyl-d-aspartate receptor encephalitis with human herpesvirus-7 present in cerebrospinal fluid have been documented, but the clinical significance of this finding remains unclear.Case presentationAn 11-year-old Caucasian boy was admitted to hospital after a generalized tonic–clonic seizure. Generalized tonic seizures repeated three more times during the day of hospitalization. Blood tests showed minor ongoing inflammation, while brain computed tomography yielded normal results. Brain magnetic resonance imaging showed hyperintense focal alterations in both temporal lobes, hippocampi, and at the base of the right frontal lobe. Positive anti-N-methyl-d-aspartate receptor antibodies were found in both serum and cerebrospinal fluid. Positive novel coronavirus 2 (severe acute respiratory syndrome coronavirus 2) immunoglobulin G antibodies were found in serum. Polymerase chain reaction test for severe acute respiratory syndrome coronavirus 2 was negative. Furthermore, positive human herpesvirus-7 deoxyribonucleic acid was found in cerebrospinal fluid. The patient was treated with acyclovir, human immunoglobulin, and methylprednisolone. The seizures did not repeat, and no psychiatric symptoms were present. The patient made a full recovery.ConclusionsWe present a pediatric case of anti-N-methyl-d-aspartate receptor encephalitis with atypical clinical presentation. The role of human herpesvirus-7 in neurological disorders remains unclear in immunocompetent patients.

Cachexia, chorea, and pain in chronic nonbacterial osteitis and inflammatory bowel disease: a case report

BackgroundInflammatory bowel disease is an inflammatory disorder that primarily impacts the gastrointestinal tract, leading to malnutrition and chronic microscopic intestinal blood loss. Uncontrolled systemic inflammation can impact other parts of the body, known as extraintestinal manifestations. Up to 25% of patients with inflammatory bowel disease are reported to have these complications in their skin, joints, bones, eyes, liver, lung, and pancreas (Rogler et al. in Gastroenterology 161(4):1118–1132, 2021). Neurologic involvement as extraintestinal manifestations are less common, reported at 3–19%, including neuropathies, demyelination, and cerebrovascular events (Morís in World J Gastroenterol. 20(5):1228–1237, 2014).Case presentationA 13-year-old Caucasian boy presented with 1 month of progressive lower-extremity pain, weakness, and weight loss. His physical examination was notable for cachexia, lower-extremity weakness, and chorea. Labs revealed normocytic anemia and systemic inflammation. Imaging revealed symmetric abnormal marrow signal in the pelvis and upper femurs. Pathologic examination of the bone revealed chronic inflammation consistent with chronic nonbacterial osteitis. Endoscopy revealed colonic inflammation consistent with inflammatory bowel disease.ConclusionsChildren and adolescents with musculoskeletal pain lasting more than 2 weeks with systemic signs or symptoms like weight loss should prompt evaluation for systemic inflammatory disorders such as chronic nonbacterial osteitis, which can occur in isolation or associated with inflammatory bowel disease. This patient also had a nonspecific neurologic abnormality, chorea, which resolved with treatment of underlying inflammatory disorder. These extraintestinal manifestations may be concurrent with or precede intestinal inflammation, requiring a high index of suspicion when investigating nonspecific systemic inflammation.

First description of congenital toxoplasmosis after maternal coinfection with Toxoplasma gondii and severe acute respiratory syndrome coronavirus 2: a case report

BackgroundCongenital toxoplasmosis can be associated with serious clinical consequences from fetus to adulthood. Hence, early detection is required to minimize severe sequelae through appropriate therapy. We describe the first case of a congenital toxoplasmosis after maternal coinfection with Toxoplasma gondii and severe acute respiratory syndrome coronavirus 2 and the challenging serological diagnosis of the disease in this context.Case presentationA Caucasian boy was born at 27 weeks 2 days of gestation by cesarean section due to maternal COVID-19-related respiratory failure. Postpartum serological screening of the mother revealed a previously unrecognized active Toxoplasma gondii infection. The premature child initially tested negative for anti- Toxoplasma gondii immunoglobulin A and M antibodies 1, 2 and 4 weeks after birth, whereas immunoglobulin G antibodies were only weakly positive with no evidence of child-specific production. Neither neurological nor ophthalmological abnormalities were detected. Approximately 3 months after birth, serological testing indicated a congenital toxoplasmosis by presence of immunoglobulin A and M, in combination with a child-specific immunoglobulin G synthesis. Additionally, cerebrospinal fluid was tested positive for Toxoplasma gondii DNA. Although no clinical manifestations of congenital toxoplasmosis were detected, an antiparasitic therapy was initiated to minimize the risk of late sequelae. There were no hints for a transplacental transmission of severe acute respiratory syndrome coronavirus 2.ConclusionThis case raises the awareness of possible coinfections with the risk of transplacental transmission in cases of maternal coronavirus disease 2019. The report emphasizes the need for screening vulnerable patients for toxoplasmosis in general and especially in the context of pregnancy. It becomes evident that prematurity can complicate the serological diagnosis of congenital toxoplasmosis due to a delayed antibody response. Repeated testing is recommended to carefully monitor children at risk and especially those with a history of preterm birth.

Residual unabsorbed midazolam: a case report

BackgroundOral midazolam is commonly administered to reduce anxiety in children presenting for medical procedures or surgery. It is unclear what volume of medication remains unabsorbed in the stomach when the child presents for anesthetic induction prior to these procedures. The presence of any significant residual medication in the stomach has significant clinical implications in the postoperative period.Case presentationA 5-year-old white Caucasian boy presented for upper gastrointestinal endoscopy after receiving oral midazolam liquid. Insertion of the endoscope into the stomach revealed a significant amount of unabsorbed medication remaining within the gastric cavity.ConclusionClinicians should be aware that the sedative effects of midazolam may be present before the medication is fully absorbed. A significant amount of unabsorbed medication may be present in the stomach during medical procedures/surgery. This may continue to be absorbed in the intraoperative and postoperative period, with unwanted clinical effect.

A Forgotten Disease Presenting with Pseudoparalysis, Petechiae and Spontaneous Gingival Bleeding in a 3-Year-Old Toddler.

A 3-year-old previously healthy Caucasian boy with a history of non-weight bearing since one week presented to our emergency department. The parents did not report pain at night or at rest or fever. He had suffered from spontaneous gingival bleedings for several days and intermittent nose bleedings for several months. A detailed dietary history revealed a fussy eater with a restricted diet entirely based on cow’s milk with dissolved cookies. He was growing appropriately on the 75th percentile. His parents and siblings were well.

Large pyogenic granuloma on the scrotum; a case report

Background: Pyogenic granuloma (PG) is a common benign vascular lesion of the skin and mucosa, which happens following different stimuli. Although the common sites for PG are the face, oral cavity, upper trunk and digits, here we report a rare case of large PG on the scrotum. Case Presentation: On 12 January 2021, a 14-year-old Caucasian boy came to the urology clinic of Alzahra hospital, Isfahan, Iran with a large pink lesion on the left hemi-scrotum, which has been gradually enlarged for the past four months with rapid growth in the last three weeks becoming 4 cm in diameter. We resected the lesion using microscopic surgery and the findings in the histopathological study were consistent with PG. Conclusion: Here we reported a rare case of teenage Caucasian boy with large PG on the scrotum for the first time. Although this lesion is rare, urologists should be familiar with it.

Alpha-gal syndrome initially misdiagnosed as chronic spontaneous urticaria in a pediatric patient: a case report and review of the literature

IntroductionDelayed allergy to red meat, also termed alpha-gal syndrome, is increasingly reported in adults and African communities, while pediatric cases remain rare.Case presentationHere, we report on a 7-year-old Caucasian boy presenting with recurrent wheals since the age of 5 years old. Episodes with hives occurred around every 3 weeks, mainly in the evening. One of these episodes was also associated with angioedema. No clear trigger was identified. At the first visit, after excluding an infection and autoimmune thyroiditis, chronic spontaneous urticaria was suspected and symptomatic treatment with antihistamines was prescribed. Six months later, the boy presented at the emergency room with generalized urticaria, dyspnoea, and emesis. Symptoms resolved after administration of epinephrine and antihistamines. A detailed medical history after this event revealed that he had eaten three sausages as well as jelly beans containing gelatine several hours prior to this episode. More precisely, after eating the sausages and jelly beans during the day, he had shown some hives before going to bed, and later developed the other symptoms in the middle of the night, suggesting alpha-gal syndrome. In his history, several tick bites are reported. Immunoglobulin E levels for alpha-gal were clearly elevated, confirming the diagnosis of a delayed-appearing immunoglobulin E-mediated allergic reaction to alpha-gal. Emergency medication was prescribed and avoidance of red meat and gelatine-containing foods was recommended. Under this exclusion diet, the boy remained asymptomatic, with the exception of two accidents in the follow up of 3 years, one developing during a barbecue and the second after exceptionally eating marshmallows.ConclusionA detailed clinical history led to the diagnosis of alpha-gal syndrome. Although alpha-gal syndrome is typically seen in adults, our case illustrates that children can also present with this potentially life-threatening allergy. Since alpha-gal syndrome is rare in Europe, the disease is not well known and often overlooked for several years, especially in children.

Longitudinal melanonychia in a 13-year-old Caucasian boy

Longitudinal melanonychia in a 13-year-old Caucasian boy

Quando la linfoistiocitosi emofagocitica è secondaria

The paper describes the case of a 1-year-old Caucasian boy with a 1-month history of fever and splenomegaly. Laboratory findings showed pancytopenia, hypertriglyceridemia and hyperferritinemia. Secondary haemophagocytic lymphohistiocytosis was suspected on the basis of clinical and laboratory features. Bone marrow aspirate revealed active haemophagocytosis without intra- or extracellular parasites. High levels of antibody title for leishmaniasis confirmed the final diagnosis of haemophagocytic syndrome secondary to visceral leishmaniasis. Amphotericin B treatment was started and showed good clinical response and improvement of laboratory parameters.

A fatal case of malignant atrophic papulosis in a pediatric patient

A 17-year-old Caucasian boy presented with progressive left-sided weakness, transient slurred speech, and skin lesions characterized by 3-5mm, pink, asymptomatic papules with white atrophic centers on his central abdomen, back, and lower extremities. Skin biopsy confirmed the diagnosis of malignant atrophic papulosis, a rare vasculopathy that leads to the occlusion of small- and medium-sized arteries. He was treated with cyclophosphamide, eculizumab, treprostinil, pentoxifylline, heparin, and acetylsalicylic acid. Despite the aggressive immunosuppression, humanized monoclonal antibodies, and antiplatelet therapy, he died two months after presentation. We report this case to highlight diagnostic features, as well as to highlight the importance of early diagnosis and treatment.

Multiple arteriectomies in a case of juvenile retinoschisis with rhegmatogenous retinal detachment

A16-year-old Caucasian boy presented himself with a sudden visual loss in his RE due to a pre-retinal haemorrhage involving the macula. A wide portion of the inferior retina ballooned into the vitreous cavity, extending from the temporal arcades to the ora serrata. Fundoscopy and B-scan ultrasound were compatible with pre-existing retinoschisis, combined with a limited area of probable full-thickness retinal detachment. X-linked retinoschisis was clinically suspected based on the presence of a circumscribed inner retinal elevation area in the inferior-temporal mid periphery of the fellow eye (siblings not available for examination because living outside the European borders).

A case report of a severe neonatal systemic vasculitis on the first day of life

BackgroundNeonatal systemic vasculitis syndromes have been reported in infants born to mothers with systemic lupus erythematosus, Sjögren’s syndrome, Behҫet’s disease, cutaneous polyarteritis nodosa and anti-neutrophil cytoplasmic antibody-associated vasculitides. Here we report a novel association of a case of new-onset maternal seronegative inflammatory arthritis associated with a transient systemic vasculitis in a neonate.Case presentationIn the first 24 h of life, a preterm Caucasian baby boy was noted to have blue discoloration to all four extremities. Despite antibiotics, fresh frozen plasma and anticoagulation, the discoloration remained, particularly in the left index finger. This was associated with fever and a maximum C-reactive protein (CRP) of 148 mg/L. Intravenous immunoglobulin (IVIG) was given with short-term improvement. Initial echocardiogram showed enlarged coronary arteries with normalization on repeat 1 week later. Clinical signs and symptoms responded to high dose oral steroid administration. MRI angiography (MRA) of the body and heart showed tortuosity of arteries in the upper and lower extremities with gadolinium uptake, suggestive of vasculitis. Autoantibody profile negative. Genetic panel for hereditary autoinflammatory diseases was negative as was whole exome sequencing performed on the trio. The baby was weaned off steroids by 5 months of age. A small distal autoamputation of the left index finger occurred.He was born to a 28-year-old woman who developed new onset severe symmetrical polyarthritis at 8 weeks gestation. This was presumed a reactive arthritis secondary to a dental infection. Infectious work up and autoantibodies were negative. She was treated with high dose prednisone for the remainder of her pregnancy.The mother was weaned off prednisone, treated with hydroxychloroquine for 8 months post-partum and remains in remission. A repeat MRA done at 1 year old showed mild residual tortuosities of the arteries in the forearms. The remainder of the medium and large vessels were within normal limits with no gadolinium enhancement to suggest active disease. The child is now 4 years old with normal growth and development.ConclusionThis is a unique case of new-onset seronegative presumed reactive arthritis in a mother with the rare development of a successfully treated medium vessel vasculitis in an infant.

Immunophenotypic challenges in diagnosis of CD79a negativity in a patient with\xa0B acute lymphoblastic leukemia harboring intrachromosomal amplification of chromosome 21: a case report

BackgroundBeing expressed in all stages of B-cell development and having a significant value on the European Group for the Immunological Characterization of Acute Leukemias scoring system, CD79a is considered as an excellent pan-marker for lineage assignment of B cells by flow cytometry. Therefore, any lack or decrease in CD79a expression makes the diagnosis of B acute lymphoblastic leukemia cases very challenging, especially in developing country laboratories where flow cytometry analyses are not always available and, when they are, they are limited in the number of markers used for lineage assignment. Since this case is potentially interesting, we report a B acute lymphoblastic leukemia case with a lack of expression CD79a associated with intrachromosomal amplification of chromosome 21 genetic abnormality. We further discuss the practical challenges in the diagnosis of this case.Case presentationWe present the case of an 8-year-old Caucasian boy from eastern Morocco who was initially hospitalized for a hemorrhagic syndrome. Peripheral blood smear examination showed a significant number of blasts suggesting acute leukemia. Bone marrow was studied for morphology, cytochemistry, immunophenotyping, and cytogenetics. Flow cytometry analyses showed expression of CD19, CD22, CD10, CD34, and HLA-DR markers by leukemic blasts. The expression of CD79a, which was checked with two different monoclonal antibodies, confirms that this marker was severely decreased in this case. Cytogenetic study performed by fluorescence in situ hybridization revealed the presence of intrachromosomal amplification of chromosome 21, a cytogenetic abnormality that is specific for B acute lymphoblastic leukemia.ConclusionCD79a is one of the critical markers in the assignment of B acute lymphoblastic leukemia. In our case, we were lucky enough to be assisted by a few other markers of the B lineage that were positive in this case. Also, we mention the importance of proceeding to cytogenetic study, which in our case helped us to confirm the diagnosis made by flow cytometry by highlighting a cytogenetic abnormality that is specific to B acute lymphoblastic leukemia.