Mutations in SLC29A3, encoding an equilibrative nucleoside transporter ENT3, cause a familial histiocytosis syndrome (Faisalabad histiocytosis) and familial Rosai-Dorfman disease.

The histiocytoses are a heterogeneous group of disorders characterised by an excessive number of histiocytes. In most cases the pathophysiology is unclear and treatment is nonspecific. Faisalabad histiocytosis (FHC) (MIM 602782) has been classed as an autosomal recessively inherited form of histiocytosis with similarities to Rosai-Dorfman disease (RDD) (also known as sinus histiocytosis with massive lymphadenopathy (SHML)). To elucidate the molecular basis of FHC, we performed autozygosity mapping studies in a large consanguineous family and identified a novel locus at chromosome 10q22.1. Mutation analysis of candidate genes within the target interval identified biallelic germline mutations in SLC29A3 in the FHC kindred and in two families reported to have familial RDD. Analysis of SLC29A3 expression during mouse embryogenesis revealed widespread expression by e14.5 with prominent expression in the central nervous system, eye, inner ear, and epithelial tissues including the gastrointestinal tract. SLC29A3 encodes an intracellular equilibrative nucleoside transporter (hENT3) with affinity for adenosine. Recently germline mutations in SLC29A3 were also described in two rare autosomal recessive disorders with overlapping phenotypes: (a) H syndrome (MIM 612391) that is characterised by cutaneous hyperpigmentation and hypertrichosis, hepatomegaly, heart anomalies, hearing loss, and hypogonadism; and (b) PHID (pigmented hypertrichosis with insulin-dependent diabetes mellitus) syndrome. Our findings suggest that a variety of clinical diagnoses (H and PHID syndromes, FHC, and familial RDD) can be included in a new diagnostic category of SLC29A3 spectrum disorder.

Diagnostic pitfalls in acute leukemia.

In most children presenting with the common signs and symptoms of leukemia, the diagnosis is readily made. However, unusual features of the disease and the absence of abnormalities on the complete blood count may render the diagnosis problematic, especially if this malignancy is not suspected. The current report focuses on the unusual presentation of leukemia and the difficulties in the diagnosis of the malignancy.

Composite adrenal anaplastic neuroblastoma and virilizing adrenocortical tumor with germline TP53 R248W mutation.

Composite tumors are extremely rare. Such tumors in adrenal glands are usually of neuroendocrine-neural type and occur mostly in adults. Their pathogenesis remains elusive. We report a patient with composite neuroblastoma (NB), adrenocortical tumor (ACT), and Li-Fraumeni syndrome (LFS) with germline TP53 R248W mutation. LFS predisposes to the development of leukemia, sarcomas, adrenocortical and breast carcinomas, brain tumors and, questionably, NB. A unique correlation between a single TP53 mutation (R337H) and ACT has been reported in southern Brazilian children. It remains unclear at this time whether a similar association of NB and R248W in patients with LFS exists.

Review of antihemophilic factor injection for the routine prophylaxis of bleeding episodes and risk of joint damage in severe hemophilia A.

Individuals with severe factor VIII deficiency experience recurrent hemorrhages and develop progressive joint damage. Large retrospective, nonrandomized studies of patient cohorts followed over decades show that factor prophylaxis initiated at an early age before the onset of recurrent bleeding reduces the incidence of hemophilic arthropathy. Two recent prospective, multicenter, randomized trials conducted in Europe (the ESPRIT study) and the USA (the Joint Outcome Study) confirm the efficacy of prophylaxis in the prevention of hemarthroses and arthropathy. Regular prophylaxis initiated in early childhood enhances the quality of life for patients with severe hemophilia and reduces the risk of inhibitor development. The substantial costs of such preventative therapy may be offset by the reduced expenditures that the care of degenerative joint disease in adult hemophilia patients would otherwise require.

Hereditary and familial syndromes of bone and blood. Genetic pathways, diagnostic pitfalls.

Numerous metabolic disorders, teratogenic agents, and in utero infections lead to congenital bone disease and malformation. This review focuses on hereditary and familial disorders of bone with particular emphasis on impaired hematopoiesis, myelofibrosis, pathologic fractures, and dysmorphology of the forearm and craniofacial structures. The severity of bone disease and marrow dysfunction of any given disorder may vary considerably from one affected individual to the next, and intrapersonal variability over time may be substantial as well. Both can impart difficulty to the appropriate evaluation and delay the correct diagnosis. Many of these disorders are phenotypically quite similar but require very different therapeutic intervention.

Faisalabad histiocytosis mimics Rosai-Dorfman disease: brothers with lymphadenopathy, intrauterine fractures, short stature, and sensorineural deafness.

Rosai-Dorfman disease (RDD) is a rare, sporadic histiocytic disorder characterized by painless but protracted lymphadenopathy. Its etiology remains unclear. The observation of congenital disease and reports of familial cases with seven pairs of siblings including three sets of identical twins suggests a genetic predisposition in some patients with this condition. We now report two brothers of consanguineous Palestinian parents, whose lymphadenopathy, lymph node histology, and polyclonal hypergammaglobulinemia indicated RDD. The presence of intrauterine fractures, short stature, and sensorineural hearing impairment suggested a rare familial form of the disorder. Moynihan et al. recently described a Pakistani family with a familial histiocytic disorder highly reminiscent of the brothers reported here, whose lymph node morphology was apparently consistent with RDD as well. The presence of sensorineural deafness, short stature, and joint contractures, however, suggested a separate, rare autosomal recessive syndrome referred to as Faisalabad histiocytosis, after the family's place of origin. We believe that the brothers described here represent a second family with Faisalabad histiocytosis, which mimics RDD histologically.

The rule of four: a systematic approach to diagnosis of common pediatric hematologic and oncologic disorders.

The "Rule of Four" facilitates a rapid and focused approach to the diagnosis of the common hematologic and oncologic disorders encountered in general pediatric practice. This system relies on four recurrent but different clinical entities or laboratory tests relevant to the diagnosis of children with anemia, excessive bleeding or clotting, and common malignancies. For each disorder, there is a discussion of a variety of four lab tests or factors pertinent to a differential diagnosis.

Familial gigantiform cementoma with brittle bone disease, pathologic fractures, and osteosarcoma: a possible explanation of an ancient mystery.

We describe four individuals of an African-American family with a predominantly diaphyseal bone disease associated with familial gigantiform cementoma (FGC), a disorder typically seen in Caucasians. The mother and her children presented with deformities of the jaws, abnormalities of the long bones, and pre-pubertal pathologic fractures. The index patient carried the diagnosis of osteosarcoma (OS). In addition, we provide a possible explanation for the jaw abnormalities of King Tutankhamen's father in the 18th dynasty in Egypt around 1350 BC.

Hepatosplenic gamma/delta T-cell lymphoma with isochromosome 7q, translocation t(7;21), and tetrasomy 8 in a 9-year-old girl.

The authors report a child younger than age 15 years with a rare hepatosplenic gamma/delta T-cell lymphoma, which is highly aggressive and primarily seen in young men. A 9-year-old girl presented with thrombocytopenia and hepatosplenomegaly. Bone marrow analysis revealed a metastatic pleomorphic lymphoma of peripheral T-cell phenotype, with rearrangement of the T-cell receptor gamma/delta and expression of CD3 and CD16/56. Instead of the previously reported primary, nonrandom, chromosomal abnormalities, isochromosome 7q and trisomy 8, this patient had four copies each of chromosome 7q, including isochromosome 7[i(7)(q10)] and der(21)t(7;21), as well as chromosome 8. This entity needs to be considered in women and children with lymphoma. Conventional therapy appears to be inadequate for cure.