Colonic adenomatous polyp with florid presence of monoclonal lambda Russell bodies: Case report and etiopathogenic hypothesis.

Russell bodies (RBs) are round eosinophilic intracytoplasmic inclusions formed by condensed immunoglobulins in mature plasma cells, which are called Mott cells. These cells are rarely found in the gastric tract, with even less cases reported in the colorectal region. There are still many questions about this event, as it is still unknown the relationship between the agents reported of increasing the probability of appearance of these cells and the generation of RBs. In this case report we describe the fifth patient presenting an infiltration of Mott cells in a colorectal polyp, being the second case with a monoclonal origin without a neoplastic cause, and the first one monoclonal for lambda. A comparison with previously similar reported cases is also done, and a possible etiopathogenic hypothesis proposed.

Choosing the Best Tissue and Technique to Detect Mosaicism in Fibrous Dysplasia/McCune-Albright Syndrome (FD/MAS).

GNAS-activating somatic mutations give rise to Fibrous Dysplasia/McCune-Albright syndrome (FD/MAS). The low specificity of extra-skeletal signs of MAS and the mosaic status of the mutations generate some difficulties for a proper diagnosis. We studied the clinical and molecular statuses of 40 patients referred with a clinical suspicion of FD/MAS to provide some clues. GNAS was sequenced using both Sanger and Next-Generation Sequencing (NGS). We were able to identify the pathogenic variants in 25% of the patients. Most of them were identified in the affected tissue, but not in blood. Additionally, NGS demonstrated the ability to detect more patients with mosaicism (8/34) than Sanger sequencing (4/39). Even if in some cases, the clinical information was not complete, we confirmed that, as in previous works, when the patients were young children with a single manifestation, such as hyperpigmented skin macules or precocious puberty, the molecular diagnosis was usually negative. In conclusion, as FD/MAS is caused by mosaic variants, it is essential to use sensitive techniques that allow for the detection of low percentages and to choose the right tissue to study. When not possible, and due to the low positive genetic rate, patients with FD/MAS should only be genetically tested when the clinical diagnosis is really uncertain.

[The enigma of Henry IV's disease: Did he suffer from McCune-Albright syndrome/fibrous dysplasia?] / El enigma de la enfermedad de Enrique IV, rey de Castilla: ¿padeció síndrome de McCune-Albright/displasia fibrosa?

BACKGROUND: Henry IV King of Castile, last king of the Trastámara dynasty, was the brother of Isabella the Catholic. He is known as "the impotent". Based on previous descriptions by historians and biographers, Gregorio Marañón in 1922 described him as "eunuchoid dysplastic with acromegalic reaction and clear schizoid features". METHODS: In 1946, a post-mortem inspection was carried out on the mummified corpse found in the Monastery of Guadalupe. A written document and some photographs were recorded. We have collected the signs and symptoms described and applied the international classification of diseases recommended by the World Health Organisation, ICD11-2023. We have relied on the coins issued in the money of Henry IV, on which we have identified enlargement of the thyroid gland. RESULTS: With the data available at this time, we suggest that Henry IV most probably suffered from: facial and polyostotic bone dysplasia, kyphosis, limb limping, multiple endocrine disorders, acromegaly with macrognatia, nodular thyroid disease, malodorous diaphoresis, erectile dysfunction, hypospadias, abnormal sexual development, "feminoid pelvis", abdominal colic, oligodontia and dental displacement. It is possible that he also suffered from: precocious puberty, renal lithiasis with debilitating phosphaturia, carpal tunnel, thrombopenia and growth hormone-producing pituitary hyperplasia or adenoma. CONCLUSION: We suggest that Henry IV may have suffered from McCune-Albrigth syndrome associated with fibrous dysplasia, a rare disease due to gain-of-function mutations in the GNAS gene.

New pathogenic variant in DLX5: New clues for a clinical spectrum from split-hand-foot malformation to fibular aplasia, tibial campomelia and oligosyndactyly.

Introduction: FATCO (Fibular Aplasia, Tibial Campomelia and Oligosyndactyly) is a very infrequent skeletal dysplasia classified within the limb hypoplasia-reduction defects group whose genetic cause has not yet been identified. The advent of next-generation sequencing is enabling the diagnosis of diseases with no previously known genetic cause. Methods: We performed a thorough autopsy on a fetus whose pregnancy was legally terminated due to severe malformations detected by ultrasound. A trio exome was run to identify the genetic cause and risk of recurrence. Previous literature of similar cases was systematically searched. Results: Anatomopathological analyses revealed complete fibular aplasia, shortened and campomelic tibia, absent ankle joint, club right foot and a split foot malformation, leading to the diagnosis of FATCO. Exome sequencing showed that the female fetus carried a de novo nonsense variant in DLX5. The literature search permitted the collection of information on 43 patients with FATCO, the majority of whom were males diagnosed postnatally. In most cases, lower limbs were affected exclusively, but in 39.5% of cases the upper limbs were also affected. Conclusion: The pathologies associated with DLX5 variants encompass a wide spectrum of manifestations ranging from abnormalities exclusively in the hands and feet to long bones such as the tibia and fibula.

[Familial endometrial adenocarcinoma: MSH6 variant of unknown significance in the presence of phenocopy, what should be done?] / Adenocarcinoma de endometrio en una familia: variante de significado incierto en MSH6 en presencia de fenocopia, ¿cómo resolverlo?

Endometrial cancer (EC) is the second most common tumor in women with Lynch syndrome, and can be its first manifestation. It may exhibit negative immunostaining for DNA mismatch-repair proteins and/or microsatellite instability. We present the case of a woman with EC in which a MSH6 variant of unknown significance was identified. To establish the pathogenicity of the variant, the family study was extended, identifying her healthy sister as a carrier while her aunt, with EC, was not. In the latter, the histopathology of a first tumor block did not identify the pathway of carcinogenesis, but its repetition in a second tumor block suggested the possibility of it being a phenocopy. The multidisciplinary approach in the study of this family allowed a correct diagnosis of the different adenocarcinomas, adequate family genetic counselling and the correct assignment of pathogenicity to a variant in MSH6.

Frequency of de novo variants and parental mosaicism in families with inactivating PTH/PTHrP signaling disorder type 2.

Objective: iPPSD2 (which includes PHP1A and PPHP/POH) is a rare inherited autosomal dominant endocrine disorder caused by inactivating GNAS pathogenic variants. A high percentage of de novo cases has been suggested. In rare cases, parental mosaicism has been described, but its real frequency is unknown. Design: A retrospective study including a series of 95 genetically confirmed iPPSD2 probands. Methods: The frequency of de novo cases was evaluated and the distribution of the type of variants was compared according to the type of inheritance. The putative involved allele was determined by reverse transcriptase PCR (RT-PCR) or allele specific oligonucleotide RT-PCR (ASO-RT-PCR). The possibility of GNAS mosaicism was studied by next-generation sequencing (NGS) on the corresponding parental DNA. Results: In 41 patients the variant was of de novo origin and in 24 the origin could not be established. In both cases 66.67% of variants generated a truncated or absent protein whereas the rest of the variants were missense or in-frame deletion/duplication. Parental origin was studied in 45 of those patients and determined in 35. Curiously, the percentage of de novo variants at the paternal allele was higher than when paternally inherited (31.1% vs 6.67%). NGS detected mosaicism in three independent families: one from paternal DNA (allelic ratio 10%) and two from maternal DNA (allelic ratio 10% and 2%). Conclusion: De novo pathogenic variants are frequent in iPPSD2 (around 45%). Parental mosaicism is infrequent (8.11%) but should be analyzed with NGS, taking into account its importance in genetic counselling.

Inactivating PTH/PTHrP signaling disorders (iPPSDs): evaluation of the new classification in a multicenter large series of 544 molecularly characterized patients.

OBJECTIVE: Pseudohypoparathyroidism and related disorders belong to a group of heterogeneous rare diseases that share an impaired signaling downstream of Gsα-protein-coupled receptors. Affected patients may present with various combination of symptoms including resistance to PTH and/or to other hormones, ectopic ossifications, brachydactyly type E, early onset obesity, short stature and cognitive difficulties. Several years ago we proposed a novel nomenclature under the term of inactivating PTH/PTHrP signaling disorders (iPPSD). It is now of utmost importance to validate these criteria and/or improve the basis of this new classification. DESIGN: Retrospective study of a large international series of 459 probands and 85 relatives molecularly characterized. METHODS: Information on major and minor criteria associated with iPPSD and genetic results were retrieved from patient files. We compared the presence of each criteria according to the iPPSD subtype, age and gender of the patients. RESULTS: More than 98% of the probands met the proposed criteria for iPPSD classification. Noteworthy, most patients (85%) presented a combination of symptoms rather than a single sign suggestive of iPPSD and the overlap among the different genetic forms of iPPSD was confirmed. The clinical and molecular characterization of relatives identified familial history as an additional important criterion predictive of the disease. CONCLUSIONS: The phenotypic analysis of this large cohort confirmed the utility of the major and minor criteria and their combination to diagnose iPPSD. This report shows the importance of having simple and easily recognizable signs to diagnose with confidence these rare disorders and supports a better management of patients.

Prenatal and foetal autopsy findings in glutaric aciduria type II.

BACKGROUND: Glutaric aciduria type 2 is a rare, lethal disorder that affects metabolism of fatty acids caused by genetic defects in electron transfer (ETF) or in electron transfer flavoprotein dehydrogenase (ETFDH). We aimed to describe the pathological findings of 15 week old foetus, born from a consanguineous couple with 3 previous perinatal deaths. The last son died at 4 days of life and genetic analyses revealed a novel probably pathogenic variant at ETFDH (c.706dupG + c.706dupG) that codifies for a truncated protein (p.Glu236Glyfs*5 + p.Glu236Glyfs*5). CASE: During the gestation, due to the medical familial history, prenatal echography and a chorial biopsy for ETFDH-associated glutaric aciduria analysis were carried out. Sanger sequencing confirmed the presence of the homozygous familial variant in the ETFDH gene. The gestation was terminated and the foetal autopsy performed. Autopsy revealed prominent forehead, flat nasal bridge, malformed ears, intrauterine growth retardation, polycystic kidneys and steatosis in the liver, consistent with the diagnosis of glutaric aciduria type II. The comparison of present cases with the previously reported in the literature confirmed the presence of classical criteria, but also revealed the association with urogenital deformities, not previously stated. CONCLUSIONS: Clinical and foetal findings allowed the characterisation of the novel variant (c.706dupG at ETDFH) as pathogenic. Genotype-phenotype relationship is important when studying rare genetic disorders such as glutaric aciduria type II, as variants are usually family-specific, leading to a difficulty in the characterisation of their pathogenicity.

Head and neck manifestations of an undiagnosed McCune-Albright syndrome: clinicopathological description and literature review.

Craniofacial fibrous dysplasia, characteristic of McCune-Albright syndrome (MAS), is usually present in patients with MAS-related acromegaly. We report here the first case of a patient with an undiagnosed MAS presenting with an acute hydrocephalus. A 21-year-old male with gigantism and craniofacial fibrous dysplasia consulted for rapidly progressive headache. An acute obstructive hydrocephalus due to a 39 × 35-mm cystic lesion in the third ventricle was discovered and operated, obtaining hydrocephalus resolution. Pathology described a colloid cyst material and a growth hormone-secreting pituitary adenoma. Genetic study revealed the mosaic GNAS R201H mutation in the pituitary tissue, confirming a MAS diagnosis. Adequate hormonal control was achieved postoperatively. Our results suggest that long-term untreated growth hormone excess in patients with MAS-related craniofacial fibrous dysplasia might end compromising cerebrospinal fluid flow. A prompt diagnosis and coordinated multidisciplinary treatment may help to avoid long-term deleterious impact of hyperfunctioning endocrinopathies in these patients.

What to consider when pseudohypoparathyroidism is ruled out: iPPSD and differential diagnosis.

BACKGROUND: Pseudohypoparathyroidism (PHP) is a rare disease whose phenotypic features are rather difficult to identify in some cases. Thus, although these patients may present with the Albright's hereditary osteodystrophy (AHO) phenotype, which is characterized by small stature, obesity with a rounded face, subcutaneous ossifications, mental retardation and brachydactyly, its manifestations are somewhat variable. Indeed, some of them present with a complete phenotype, whereas others show only subtle manifestations. In addition, the features of the AHO phenotype are not specific to it and a similar phenotype is also commonly observed in other syndromes. Brachydactyly type E (BDE) is the most specific and objective feature of the AHO phenotype, and several genes have been associated with syndromic BDE in the past few years. Moreover, these syndromes have a skeletal and endocrinological phenotype that overlaps with AHO/PHP. In light of the above, we have developed an algorithm to aid in genetic testing of patients with clinical features of AHO but with no causative molecular defect at the GNAS locus. Starting with the feature of brachydactyly, this algorithm allows the differential diagnosis to be broadened and, with the addition of other clinical features, can guide genetic testing. METHODS: We reviewed our series of patients (n = 23) with a clinical diagnosis of AHO and with brachydactyly type E or similar pattern, who were negative for GNAS anomalies, and classify them according to the diagnosis algorithm to finally propose and analyse the most probable gene(s) in each case. RESULTS: A review of the clinical data for our series of patients, and subsequent analysis of the candidate gene(s), allowed detection of the underlying molecular defect in 12 out of 23 patients: five patients harboured a mutation in PRKAR1A, one in PDE4D, four in TRPS1 and two in PTHLH. CONCLUSIONS: This study confirmed that the screening of other genes implicated in syndromes with BDE and AHO or a similar phenotype is very helpful for establishing a correct genetic diagnosis for those patients who have been misdiagnosed with "AHO-like phenotype" with an unknown genetic cause, and also for better describing the characteristic and differential features of these less common syndromes.

Parathyroid hormone resistance syndromes - Inactivating PTH/PTHrP signaling disorders (iPPSDs).

Metabolic disorders caused by impairments of the Gsα/cAMP/PKA pathway affecting the signaling of PTH/PTHrP lead to features caused by non-responsiveness of target organs, in turn leading to manifestations similar to the deficiency of the hormone itself. Pseudohypoparathyroidism (PHP) and related disorders derive from a defect of the α subunit of the stimulatory G protein (Gsα) or of downstream effectors of the same pathway, such as the PKA regulatory subunit 1A and the phosphodiesterase type 4D. The increasing knowledge on these diseases made the actual classification of PHP outdated as it does not include related conditions such as acrodysostosis (ACRDYS) or progressive osseous heteroplasia (POH), so that a new nomenclature and classification has been recently proposed grouping these disorders under the term "inactivating PTH/PTHrP signaling disorder" (iPPSD). This review will focus on the pathophysiology, clinical and molecular aspects of these rare, heterogeneous but closely related diseases.

Familial Progressive Hyperpigmentation, Cutaneous Mastocytosis, and Gastrointestinal Stromal Tumor as Clinical Manifestations of Mutations in the c-KIT Receptor Gene.

BACKGROUND: Familial progressive hyperpigmentation (FPH) is an autosomal dominant disorder characterized by the appearance of hyperpigmented patches on the skin from early infancy that increase in size and number with age. METHODS: We report the clinical and molecular studies of an 11-year-old boy who had areas of hyperpigmentation since birth that had spread across his body as irregular hyperpigmented macules and papules, and include relevant history in family members. RESULTS: Affected members of his family shared a mutation in the c-KIT gene. All had progressive hyperpigmentation, in some cases accompanied by gastrointestinal stromal tumors and mastocytoma. There have been few reports of familial progressive hyperpigmentation together with systemic manifestations. CONCLUSIONS: Molecular analysis of c-KIT should be considered in the presence of FPH with systemic involvement.

Disomy as the genetic underlying mechanisms of loss of heterozigosity in SDHD-paragangliomas.

CONTEXT: Succinate dehydrogenase complex, subunit D (SDHD) mutations cause pheochromocytoma/paraganglioma syndrome. SDHD, located at chromosome 11q23, shows a parent-of-origin effect because the disease is observed almost exclusively when the mutation is transmitted from the father, although some cases of maternal transmission have been reported. Several hypotheses have been proposed for this peculiar inheritance pattern, but the underlying mechanisms have not yet been clearly elucidated. OBJECTIVE: The objective of the study was to explain the parent-of-origin effect in a family, mainly affected by paternally transmitted paragangliomas, and with a maternally transmitted renal tumor. PATIENTS: Peripheral blood DNA from 15 carriers and 7 tumor DNA samples from SDHD-p.Trp5* carriers were studied. METHODS: We conducted mutation genotyping and microsatellite marker analysis in germline and tumor DNA and methylation status analysis in tumor DNA by methylation-specific multiplex ligation-dependent probe amplification. RESULTS: Mutation genotyping and microsatellite marker analysis demonstrated loss of heterozygosity of the wild-type allele (maternal) in all studied tumors, except the renal tumor, which lost the mutated allele (maternal), and the prostate tumor, which had no loss of heterozygosity. The methylation-specific multiplex ligation-dependent probe amplification demonstrated that the methylation profile corresponded exclusively to the paternal chromosome without genomic loss, suggesting paternal uniparental disomy as the mechanism underlying the parent-of-origin effect in this SDHD family. CONCLUSIONS: The paternal uniparental disomy involves the loss of maternally imprinted cell cycle regulators and the overexpression of paternally imprinted growth activators, leading to tumorigenesis in this syndrome.

PRKAR1A and PDE4D mutations cause acrodysostosis but two distinct syndromes with or without GPCR-signaling hormone resistance.

CONTEXT: Acrodysostosis is a rare skeletal dysplasia that is associated with multiple resistance to G protein-coupled receptor (GPCR) signaling hormones in a subset of patients. Acrodysostosis is genetically heterogeneous because it results from heterozygous mutations in PRKAR1A or PDE4D, two key actors in the GPCR-cAMP-protein kinase A pathway. OBJECTIVE: Our objective was to identify the phenotypic features that distinguish the two genotypes causing acrodysostosis. PATIENTS AND METHODS: Sixteen unrelated patients with acrodysostosis underwent a candidate-gene approach and were investigated for phenotypic features. RESULTS: All patients had heterozygous de novo mutations. Fourteen patients carried a PRKAR1A mutation (PRKAR1A patients), five each a novel PRKAR1A mutation (p.Q285R, p.G289E, p.A328V, p.R335L, or p.Q372X), nine the reported PRKAR1A p.R368X mutation; two patients harbored a mutation in PDE4D (PDE4D patients) (one novel mutation, p.A227S; one reported, p.E590A). All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH. Two PRKAR1A patients each with a novel mutation presented a specific pattern of brachydactyly. One PDE4D patient presented with acroskyphodysplasia. Additional phenotypic differences included mental retardation in PDE4D patients. In addition, we report the presence of pigmented skin lesions in PRKAR1A and PDE4D patients, a feature not yet described in the acrodysostosis entity. CONCLUSIONS: All PRKAR1A and PDE4D patients present similar bone dysplasia characterizing acrodysostosis. Phenotypic differences, including the presence of resistance to GPCR-cAMP signaling hormones in PRKAR1A but not PDE4D patients, indicate phenotype-genotype correlations and highlight the specific contributions of PRKAR1A and PDE4D in cAMP signaling in different tissues.

Constitutional mosaic genome-wide uniparental disomy due to diploidisation: an unusual cancer-predisposing mechanism.

Molecular studies in a patient with Beckwith-Wiedemann syndrome phenotype who developed two different tumours revealed an unexpected observation of almost complete loss of heterozygosity of all chromosomes. It is shown, by means of numerous molecular methods, that the absence of maternal contribution in somatic cells is due to high-degree (∼ 85%) genome-wide paternal uniparental disomy (UPD). The observations indicate that the genome-wide UPD results from diploidisation, and have important implications for genetic counselling and tumour surveillance for the growing number of UPD associated imprinting disorders.

Intragenic GNAS deletion involving exon A/B in pseudohypoparathyroidism type 1A resulting in an apparent loss of exon A/B methylation: potential for misdiagnosis of pseudohypoparathyroidism type 1B.

CONTEXT: Several endocrine diseases that share resistance to PTH are grouped under the term pseudohypoparathyroidism (PHP). Patients with PHP type Ia show additional hormone resistance, defective erythrocyte G(s)alpha activity, and dysmorphic features termed Albright's hereditary osteodystrophy (AHO). Patients with PHP-Ib show less diverse hormone resistance and normal G(s)alpha activity; AHO features are typically absent in PHP-Ib. Mutations affecting G(s)alpha coding exons of GNAS and epigenetic alterations in the same gene are associated with PHP-Ia and -Ib, respectively. The epigenetic GNAS changes in familial PHP-Ib are caused by microdeletions near or within GNAS but without involving G(s)alpha coding exons. OBJECTIVE: We sought to identify the molecular defect in a patient who was diagnosed with PHP-Ia based on clinical presentation (hormone resistance and AHO) but displayed the molecular features typically associated with PHP-Ib (loss of methylation at exon A/B) without previously described genetic mutations. METHODS: Microsatellite typing, comparative genome hybridization, and allelic dosage were performed for proband and her parents. RESULTS: Comparative genome hybridization revealed a deletion of 30,431 bp extending from the intronic region between exons XL and A/B to intron 5. The same mutation was also demonstrated, by PCR, in the patient's mother, but polymorphism and allele dosage analyses indicated that she had this mutation in a mosaic manner. CONCLUSION: We discovered a novel multiexonic GNAS deletion transmitted to our patient from her mother who is mosaic for this mutation. The deletion led to different phenotypic manifestations in the two generation and appeared, in the patient, as loss of GNAS imprinting.