Cows' milk allergy in the syndrome of thrombocytopenia with absent radius

Whole Exome Sequencing Identifies Epithelial and Immune Dysfunction-Related Biomarkers in Food Protein-Induced Enterocolitis Syndrome

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a food allergy primarily affecting infants, often leading to vomiting and shock. Due to its poorly understood pathophysiology and lack of specific biomarkers, diagnosis is frequently delayed. Understanding FPIES genetics can shed light on disease susceptibility and pathophysiology-key to developing diagnostic, prognostic, preventive and therapeutic strategies. Using a well-characterised cohort of patients we explored the potential genome-wide susceptibility factors underlying FPIES.

METHODS

Blood samples from 41 patients with oral food challenge-proven FPIES were collected for a comprehensive whole exome sequencing association study.

RESULTS

Notable genetic variants, including rs872786 (RBM8A), rs2241880 (ATG16L1) and rs2289477 (ATG16L1), were identified as significant findings in FPIES. A weighted SKAT model identified six other associated genes including DGKZ and SIRPA. DGKZ induces TGF-β signalling, crucial for epithelial barrier integrity and IgA production; RBM8A is associated with thrombocytopenia absent radius syndrome, frequently associated with cow's milk allergy; SIRPA is associated with increased neutrophils/monocytes in inflamed tissues as often observed in FPIES; ATG16L1 is associated with inflammatory bowel disease. Coexpression correlation analysis revealed a functional correlation between RBM8A and filaggrin gene (FLG) in stomach and intestine tissue, with filaggrin being a known key pathogenic and risk factor for IgE-mediated food allergy. A transcriptome-wide association study suggested genetic variability in patients impacted gene expression of RBM8A (stomach and pancreas) and ATG16L1 (transverse colon).

CONCLUSIONS

This study represents the first case-control exome association study of FPIES patients and marks a crucial step towards unravelling genetic susceptibility factors underpinning the syndrome. Our findings highlight potential factors and pathways contributing to FPIES, including epithelial barrier dysfunction and immune dysregulation. While these results are novel, they are preliminary and need further validation in a second cohort of patients.

Lateral thinking in syndromic congenital cardiovascular disease

Syndromic birth defects are rare diseases that can present with seemingly pleiotropic comorbidities. Prime examples are rare congenital heart and cardiovascular anomalies that can be accompanied by forelimb defects, kidney disorders and more. Whether such multi-organ defects share a developmental link remains a key question with relevance to the diagnosis, therapeutic intervention and long-term care of affected patients. The heart, endothelial and blood lineages develop together from the lateral plate mesoderm (LPM), which also harbors the progenitor cells for limb connective tissue, kidneys, mesothelia and smooth muscle. This developmental plasticity of the LPM, which founds on multi-lineage progenitor cells and shared transcription factor expression across different descendant lineages, has the potential to explain the seemingly disparate syndromic defects in rare congenital diseases. Combining patient genome-sequencing data with model organism studies has already provided a wealth of insights into complex LPM-associated birth defects, such as heart-hand syndromes. Here, we summarize developmental and known disease-causing mechanisms in early LPM patterning, address how defects in these processes drive multi-organ comorbidities, and outline how several cardiovascular and hematopoietic birth defects with complex comorbidities may be LPM-associated diseases. We also discuss strategies to integrate patient sequencing, data-aggregating resources and model organism studies to mechanistically decode congenital defects, including potentially LPM-associated orphan diseases. Eventually, linking complex congenital phenotypes to a common LPM origin provides a framework to discover developmental mechanisms and to anticipate comorbidities in congenital diseases affecting the cardiovascular system and beyond.

Case report: Pneumatosis in a neonate with thrombocytopenia absent radius syndrome

BACKGROUND

Thrombocytopenia absent radius (TAR) syndrome is a rare disease with an estimated prevalence of one in 200,000 live births. TAR is associated with cardiac and renal anomalies as well as gastrointestinal problems such as CMPA. Typically neonates with CMPA present with mild intolerance, with few reports in the literature of more severe intolerance resulting in pneumatosis. We present a case of a male infant with thrombocytopenia absent radius (TAR) syndrome who developed gastric and colonic pneumatosis intestinalis.

CASE DESCRIPTION

An eight-day-old male infant born at 36 weeks gestation with a diagnosis of TAR, presented with bright red blood in his stool. At this time he was on full formula feeds. Given continued bright red blood within his stool, an abdominal radiograph was obtained which was consistent with colonic and gastric pneumatosis. A complete blood count (CBC) was notable for worsening thrombocytopenia, anemia and eosinophilia. Once enteral feeds were held there was rapid resolution of the radiographic findings and resolution of his bloody stool. He was ultimately diagnosed with a cow's milk protein allergy (CMPA).

CONCLUSION

Though there are reports of CMPA in patients with TAR, the severity of this patient's presentation with both colonic and gastric pneumatosis is unique. Without the knowledge of the association of CMPA with TAR, this case could have been misdiagnosed and led to reintroduction of cow's milk containing formula, resulting in further complications. This case highlights the importance of a timely diagnosis and severity of CMPA in this population.

1q21.1 deletion and a rare functional polymorphism in siblings with thrombocytopenia-absent radius-like phenotypes

Thrombocytopenia-absent radii (TAR) syndrome, characterized by neonatal thrombocytopenia and bilateral radial aplasia with thumbs present, is typically caused by the inheritance of a 1q21.1 deletion and a single-nucelotide polymorphism in RBM8A on the nondeleted allele. We evaluated two siblings with TAR-like dysmorphology but lacking thrombocytopenia in infancy. Family NCI-107 participated in an IRB-approved cohort study and underwent comprehensive clinical and genomic evaluations, including aCGH, whole-exome, whole-genome, and targeted sequencing. Gene expression assays and electromobility shift assays (EMSAs) were performed to evaluate the variant of interest. The previously identified TAR-associated 1q21.1 deletion was present in the affected siblings and one healthy parent. Multiple sequencing approaches did not identify previously described TAR-associated SNPs or mutations in relevant genes. We discovered rs61746197 A > G heterozygosity in the parent without the deletion and apparent hemizygosity in both siblings. rs61746197 A > G overlaps a RelA–p65 binding motif, and EMSAs indicate the A allele has higher transcription factor binding efficiency than the G allele. Stimulation of K562 cells to induce megakaryocyte differentiation abrogated the shift of both reference and alternative probes. The 1q21.1 TAR-associated deletion in combination with the G variant of rs61746197 on the nondeleted allele is associated with a TAR-like phenotype. rs61746197 G could be a functional enhancer/repressor element, but more studies are required to identify the specific factor(s) responsible. Overall, our findings suggest a role of rs61746197 A > G and human disease in the setting of a 1q21.1 deletion on the other chromosome.

Ranitidine-induced Thrombocytopenia in a Neonate - A Case Report and Review of Literature

Thrombocytopenia (platelet count <150 × 10⁹/L) regularly occurs in newborns but is especially observed in critically ill neonates. We describe the case of a small for gestational age (SGA) neonate, who showed an unexpected, severe thrombocytopenia (8 × 10⁹/L) at day 5 of life. The thrombocytopenia recovered completely after cessation of ranitidine (0.5 mg/kg/6 hr), which was started in a context of feeding difficulties. Other causes of neonatal thrombocytopenia were ruled out. Besides a brief report on a cimetidine-induced thrombocytopenia over 25 years ago, no other neonatal or pediatric cases of H₂ antagonist-induced thrombocytopenia have been reported to date, although being widely used in routine care. Moreover, several adult cases have been published. In general, neonatal thrombocytopenia, although one of the most frequent hematological conditions in newborns, is only rarely attributed to an adverse drug reaction. Clinicians should be aware of the risks for adverse reactions, especially in routinely used drugs and in critically ill patients.

Thrombocytopenia absent radius (TAR) syndrome: a case report and review for oral health care providers

Thrombocytopenia Absent Radius (TAR) syndrome is a rare genetic disorder characterized by thrombocytopenia and bilateral absence of radii with both thumbs present. Multiple organ systems may be affected in patients with TAR syndrome, including hematologic, skeletal, cardiovascular, and gastrointestinal systems. This article describes a 35-year-old Caucasian male with TAR syndrome receiving comprehensive dental care and reviews the pertinent aspects of this disease, as well as dental management considerations, for patients with TAR syndrome.

Acute lymphoblastic leukemia in a patient with constitutional chromosome 1pter-p36.31 duplication and 1q43-qter deletion

Chromosome 1 is the largest of all human chromosomes, containing 3141 genes. It is linked to 890 known genetic diseases including congenital hypothyroidism, hemochromatosis, and prostate cancer. Recognized deletion and duplication syndromes have been described. Deletions in the short arm (p) of the chromosome have been identified in tumors of the brain and kidneys. Duplications in the long (q) arm of the chromosome are reported in myelodysplastic syndromes. Solitary 1p36 deletion or 1q42 duplication are rarely reported entities and their associations with malignancy have not been characterized. We report a case of a child with constitutional 1pter-p36.31 duplication and 1q43-qter deletion who developed acute lymphoblastic leukemia (ALL). The patient's oncologic presentation and subsequent clinical course raise the question of the association of the underlying genetic abnormality and its malignant potential, specifically in relation to ALL. Acquired chromosome 1 deletions and duplications have been well described in other malignant diseases. Constitutional chromosome 1p duplication and 1q deletions have not been described with ALL.

Management of children with thrombocytopenia-absent radius syndrome: an institutional experience

AIM

Thrombocytopenia-absent radius (TAR) syndrome is characterised by bilateral absence of the radii in the presence of both thumbs and hypomegakaryocytic thrombocytopenia. We report our experience of three patients affected by TAR syndrome presenting with different clinical manifestations focusing on the management of these patients.

METHODS AND RESULTS

We propose the use of long-term central venous catheters to reduce discomfort because of repeated vein punctures in search for a venous access, rendered difficult by upper limbs abnormalities.

CONCLUSIONS

It is important to improve the quality of life of affected patients.

Thrombocytopenia as an adverse effect of complementary and alternative medicines, herbal remedies, nutritional supplements, foods, and beverages

BACKGROUND

Thrombocytopenia is a well-recognized adverse effect of many drugs. However, the association of thrombocytopenia with complementary/alternative medicines, herbal remedies, nutritional supplements, foods, and beverages has been rarely described, except for reports of thrombocytopenia caused by quinine-containing beverages.

OBJECTIVES

To systematically identify all published reports of thrombocytopenia associated with these substances and to assess the evidence supporting their causal association with thrombocytopenia.

METHODS

Eleven databases were searched to identify relevant published reports. A priori criteria were defined for article selection and assessment. Each selected article was independently assessed by the three authors to document the presence of the criteria and determine the level of evidence for a causal association of the reported substance with thrombocytopenia.

RESULTS

Twenty-seven articles were identified that reported the occurrence of thrombocytopenia with 25 substances (other than quinine). However, only six articles describing five substances (cow's milk, cranberry juice, Jui [Chinese herbal tea], Lupinus termis bean, and tahini [pulped sesame seeds]) reported clinical data supporting definite evidence of a causal association with thrombocytopenia. Four articles provided probable evidence for four additional substances, and five articles provided possible evidence for five additional substances. In the remaining articles, the association with thrombocytopenia was unlikely or the articles were excluded from review.

CONCLUSIONS

Reports of thrombocytopenia describing definite or probable evidence for an association of a complementary/alternative medicines, herbal remedies, nutritional supplements, foods, and beverages are rare. Whether the occurrence of thrombocytopenia with these substances is uncommon or unrecognized is unknown.

Inherited Thrombocytopenia: Congenital Amegakaryocytic Thrombocytopenia and Thrombocytopenia With Absent Radii

Thrombocytopenia in the newborn period can signify an inherited platelet disorder. Congenital amegakaryocytic thrombocytopenia (CAMT) and thrombocytopenia with absent radii (TAR) share features of isolated thrombocytopenia, reduced or absent marrow megakaryocytes, impaired responsiveness to thrombopoietin (TPO), and high plasma TPO levels. These disorders are most readily distinguished from each other by the finding of radial aplasia in TAR and the presence of c-MPL mutations in CAMT. In addition, their long-term outcomes are strikingly different: the development of trilineage marrow failure in CAMT in contrast to the general improvement of thrombocytopenia in TAR. The differential diagnosis for CAMT and TAR also includes other congenital disorders in which thrombocytopenia and radial abnormalities can be seen. In this article we will review our molecular and clinical understanding of these two inherited disorders of amegakaryocytosis.

Thrombocytopenia-absent radius syndrome: a clinical genetic study

The thrombocytopenia-absent radius (TAR) syndrome is a congenital malformation syndrome characterised by bilateral absence of the radii and a thrombocytopenia. The lower limbs, gastrointestinal, cardiovascular, and other systems may also be involved. Shaw and Oliver in 1959 were the first to describe this condition, but it was Hall et al in 1969 who reported the first major series of patients. Since then most reports have been based on single or small numbers of cases. We report the results of a clinical study looking at the phenotype of 34 patients with TAR syndrome. All cases had a documented thrombocytopenia and bilateral radial aplasia, 47% had lower limb anomalies, 47% cow's milk intolerance, 23% renal anomalies, and 15% cardiac anomalies. Congenital anomalies not previously described in association with TAR syndrome included facial capillary haemangiomata, intracranial vascular malformation, sensorineural hearing loss, and scoliosis. Karyotype analysis, chromosome breakage studies including premature centromeric separation and fluorescence in situ hybridisation studies looking for a deletion of chromosome 22q11 were undertaken. Two abnormal karyotypes were identified.

Unusual presentations of food allergy

OBJECTIVE

This presentation is designed to critically review information on presentations of food hypersensitivity reactions that may be considered unusual regarding the source or nature of allergen, route of exposure, or clinical manifestation.

DATA SOURCES

Information has been gathered primarily through a thorough search of the English literature relevant to human subjects. Some clinical cases were also included from the author's own clinical experience.

STUDY SELECTION

Information summarized here was critically selected on the basis of proven or acceptable scientific validity.

RESULTS

The findings indicate that food allergy presentation can be unusual in three main aspects. First, the offending allergen may not be the obvious food that was ingested or be a food protein incorporated in a nonfood product. Second, systemic reactions can be provoked by very minute quantities of food allergens that may even get access through noningestant routes, eg, inhalation, odor, skin contact, or mucous membrane contact. Third, the clinical manifestations are not limited to the few gastrointestinal, cutaneous, and respiratory symptoms with which we are generally familiar.

CONCLUSIONS

The extent of food allergy presentation is more than has been generally realized. Our awareness of such unusual presentations adds new knowledge and should prompt our interest in carefully evaluating patients with obscure allergic reactions for possible food allergy.

Thrombocytopenia with absent radii syndrome: studies on serum thrombopoietin levels and megakaryopoiesis in vitro

PURPOSE

The pathogenesis of thrombocytopenia in patients with thrombocytopenia with absent radii (TAR) syndrome has not been clarified yet.

PATIENTS AND METHODS

This is the first report of a Japanese patient with TAR syndrome. We studied his megakaryopoiesis in vitro and serum levels of thrombopoietin (TPO).

RESULTS

Serum levels of TPO in the patient with TAR syndrome were comparable with those of an age-matched control. The bone marrow cells from the patient with TAR syndrome actually generated megakaryocyte colonies in the presence of TPO and the numbers were significantly greater than those from the age-matched control marrow. However, megakaryocyte colonies from the marrow cells with TAR syndrome contained a much lower number of cells per colony and the size of the individual megakaryocytes appeared to be smaller.

CONCLUSION

These data suggest that megakaryocyte progenitors from patients with TAR syndrome may have decreased proliferative and differentiative capacity to respond to TPO, leading to thrombocytopenia.

Clinical symptoms of food allergy/intolerance in children

Food allergy is principally a problem in infancy and early childhood. Food allergy/intolerance may cause a broad spectrum of symptoms and signs in children, including generalized reactions, such as anaphylactic shock. Reactions are localized mainly in the gastrointestinal tract, but food allergy/intolerance may also cause local symptoms in other organs such as the skin and the respiratory tract. About 50-70% demonstrate cutaneous symptoms, 50-60% gastrointestinal symptoms, and 20-30% respiratory symptoms. Among young children with food allergy/intolerance the majority have two or more symptoms with symptoms occurring in two or more organ systems. The symptoms occur primarily within a few minutes after food exposure (immediate reactions), however delayed reactions in the skin, gastrointestinal tract and lungs may also occur. Among children with symptoms suggestive of food allergy/intolerance, the diagnosis can be confirmed by controlled elimination/challenge procedures only in about one third of the patients. A proper diagnosis is important in order to avoid unnecessary restrictive diets and risk of malnutrition.

Thrombocytopenia with absent radii (TAR) syndrome: a new increased cellular radiosensitivity syndrome

A 70-year-old woman with congenital absence of both radii but preservation of the thumb developed a marked pancytopenia after two i.v. injections of 1 g of 5-fluorouracil (5-FU) 1 week apart. She developed bloody diarrhoea after nine fractions of 2 Gy to parallel opposed 16 x 15 cm abdominal fields. This unusual response prompted an investigation of the radiosensitivity of the patient's cells by the sensitive G2 assay of transformed lymphocytes. The radiosensitivity of the patient's lymphoblastoid line appeared to be intermediate between that of normal individuals and an ataxia telangiectasia line. The clinical response and in vitro radiosensitivity testing suggest that the thrombocytopenia with absent radii (TAR) syndrome appears to be one of the inherited impaired DNA repair syndromes and is a very newly described radiation sensitivity syndrome. The development of three separate primary cancers in this patient (small bowel, ovary and bladder) suggests there is an increased risk of neoplasia in this condition.

TAR-like syndrome in a consanguineous Mayan girl

We report on a 3-month-old girl with a TAR-like syndrome. Her older brother died with a similar disorder at 3 months of unknown causes. The parents are second cousins of Mayan ancestry. The infant also had, in addition to the usual abnormalities of TAR syndrome, depressed nasal bridge, cataracts, glaucoma, megalocorneae, and blue sclerae.

Thrombocytopenia and absent radius (TAR) syndrome

We give details of seven children with the TAR syndrome, Thrombocytopenia with absence of the radius. Two of the children were siblings. The TAR syndrome is characterised by hypomegakaryocytic thrombocytopenia and bilateral absence of the radius. It is inherited as an autosomal recessive trait.

Intermittent thrombocytopenia and absent radii: report of a patient with additional unusual manifestations

We report on a boy with absent radii and intermittent thrombocytopenia. He has many other manifestations of the thrombocytopenia absent radius (TAR) syndrome but in addition has manifestations not previously described: palatoschisis of the soft palate, subcricoid stenosis, duodenal atresia and extreme sensitivity of chromosomes to X-rays. Our patient could either represent a unique condition or unusual variability of TAR syndrome.

Clinical manifestations of the thrombocytopenia and absent radii (TAR) syndrome

Six patients with the classical features of the TAR syndrome were diagnosed at birth. In one case an older sibling was also affected. The characteristic features of foreshortened forearms and radially deviated hands were noted in all cases at presentation and confirmed radiologically. With one exception skeletal abnormalities of the lower limbs were also present. Varying degrees of thrombocytopenia were present at birth with three of the five patients having platelet counts below 50 x 10(9)/L. Bone marrow examination was performed in two patients and revealed an absence of normal megakaryocytes. Two patients with severe thrombocytopenia had bleeding complications during infancy requiring transfusion support. Severe gastroenteritis occurred in two patients, in one of whom it was attributed to cow's milk intolerance. In all patients the platelet count has risen progressively since birth. Orthopedic surgical procedures have been performed without hemorrhagic complications.

Food allergy and intolerance

In summary, there has been a dramatic increase in our understanding of food allergy as a result of research in immune mechanisms and clinical studies over the last decade. The subject has been comprehensively reviewed in a major new publication (Brostoff and Challacombe, 1986).

Thrombocytopenia and absent radius (TAR) syndrome

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Manifestations of milk allergy in infancy: clinical and immunologic findings

In a study of the manifestations of cow milk allergy in 100 young children (mean age 16 months), 30 items of historical data and information relating to the effects of a standardized milk challenge were entered into a computer data base. Three clusters of patients were derived using a K-means algorithm. In group 1 were 27 patients with predominantly urticarial and angioedematous eruptions, which developed within 45 minutes of ingesting cow milk. They had positive skin test reactions to milk and elevated total and milk specific IgE serum antibody levels. In group 2, 53 patients had pallor, vomiting, or diarrhea between 45 minutes and 20 hours after milk ingestion. These children were relatively IgA deficient. The 20 patients in group 3 had eczematous or bronchitic or diarrheal symptoms; in 17 symptoms developed more than 20 hours after commencing milk ingestion. Of the patients in group 3, only those with eczema had a positive skin test reaction and elevated IgE antibodies to milk. The patients in group 3 were the most difficult to identify clinically; they had a history of chronic ill health, and symptoms developed many hours or days after commencing milk ingestion in the challenge situation. In view of the heterogeneous clinical and immunologic findings in our patients, it is unlikely that a single laboratory test will identify cow milk allergy in all susceptible patients.

Thrombocytopenia with absent radii (the TAR syndrome)

The congenital association of thrombocytopenia and absent radii has been designated the TAR syndrome. This article describes a female with the TAR syndrome who presented with the first known onset of hemorrhagic phenomenon at the age of 47, the oldest age of onset described in the literature. The incidence, clinical manifestations, differential diagnosis, course, and effects of treatment of the syndrome are reviewed, and proposed etiologic factors are discussed.

Anatomical analysis of the developmental effects of aneuploidy in man--the 18-trisomy syndrome: II. Anomalies of the upper and lower limbs

We report the anatomical variations of the limbs in eight infants with the trisomy-18 syndrome that were dissected and studied in detail. In each case, the upper limbs showed defects which further define the specific influence of this aneuploidy on the development of its preaxial (radial) component, and the tendency towards reduction defects. Abnormalities included muscle variations concentrated along the radial margin of the forearm and hand, the absence of the definitive musculocutaneous nerve in all of the limbs, and reductions of the radial artery in four of the bodies. Pathogenetic mechanisms explaining the observed defects are discussed, and include: 1) a defect in peripheral nerve development; or 2) tissue necrosis. The characteristic flexion deformities of the fingers seem to be due to a displacement of the tendons of extensors digitorum and digiti minimi. The lower limbs did not show a consistent pattern of defects, except for the absence of some muscles (psoas minor, the tendon of flexor digitorum brevis to digit V), and the presence of several supernumerary muscles. These variations are discussed as possible nonspecific effects of 18-trisomy on development. The additional anatomical data from this and the first paper in this series [Bersu and Ramirez-Castro, 1977] provide a more detailed picture of the trisomy-18 phenotype which may be useful in corroborating an unconfirmed clinical diagnosis of the syndrome.