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Introduction: Myhre syndrome (MS) is an ultra-rare disorder due to pathogenic variants in the SMAD4 gene that encodes a protein regulating the TGF-β pathway and extra-cellular matrix (ECM) homeostasis. Main clinical features of MS include thickening of skin and joint stiffness. Previous studies showed that losartan improved ECM deposition in MS fibroblasts., Materials and Methods: Four molecularly confirmed MS subjects (mean age 23.8 ± 17 years) were evaluated for: (a) skin thickness by Rodnan score, (b) joint range of motion (ROM) by goniometry, and (c) speckle-tracking echocardiogram. Following baseline evaluations, three MS individuals received losartan for 12 months and pre-defined endpoints were monitored after 6 and 12 months of treatment., Results: At baseline, Rodnan scores were increased, joint ROM was reduced, and speckle-tracking echocardiogram revealed reduced myocardial strain. In three MS subjects, improvements in skin thickness, joint ROM and to a lesser extent of myocardial strain, were observed after 6 and 12 months of losartan treatment., Conclusions: Although further long-term controlled clinical trials with a larger number of affected individuals are needed, the present study suggests that losartan might improve skin, joint and heart abnormalities of MS., (© 2020 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals LLC.)

Potassium channels are a heterogeneous group of membrane-bound proteins, whose functions support a diverse range of biological processes. Genetic disorders arising from mutations in potassium channels are classically recognized by symptoms arising from acute channel dysfunction, such as periodic paralysis, ataxia, seizures, or cardiac conduction abnormalities, often in a patient with otherwise normal examination findings. In this chapter, we review a distinct subgroup of rare potassium channelopathies whose presentations are instead suggestive of a developmental disorder, with features including intellectual disability, craniofacial dysmorphism or other physical anomalies. Known conditions within this subgroup are: Andersen-Tawil syndrome, Birk-Barel syndrome, Cantú syndrome, Keppen-Lubinsky syndrome, Temple-Baraitser syndrome, Zimmerman-Laband syndrome and a very similar disorder called Bauer-Tartaglia or FHEIG syndrome. Ion channelopathies are unlikely to be routinely considered in the differential diagnosis of children presenting with developmental concerns, and so detailed description and photographs of the clinical phenotype are provided to aid recognition. For several of these disorders, functional characterization of the genetic mutations responsible has led to identification of candidate therapies, including drugs already commonly used for other indications, which adds further impetus to their prompt recognition. Together, these cases illustrate the potential for mechanistic insights gained from genetic diagnosis to drive translational work toward targeted, disease-modifying therapies for rare disorders., (© 2020 Elsevier Inc. All rights reserved.)

Cold-induced sweating syndrome (CISS) is a rare autosomal recessive disease due to mutation in the Cytokine receptor-like factor 1 (CRLF1). The characteristic symptom of CISS is the tendency to sweat profusely especially in the upper body and hands when the patient is exposed to cold temperature. We sought to first report the findings of autonomic reflex screen in a case of CISS type 1 with Cytokine receptor-like factor 1 mutation. Valsalva morphology, Valsalva ratio, and heart rate response to deep breathing were normal for the patient's age. Quantitative sudomotor axon reflex test showed nonlength dependent decrease in the sweat volume. Tilt table revealed evidence of reflex (vasovagal) "syncope," however, the patient was asymptomatic without loss of consciousness.

Purpose of Review: We give an update on the etiology and potential treatment options of rare inherited monogenic disorders associated with arterial calcification and calcific cardiac valve disease., Recent Findings: Genetic studies of rare inherited syndromes have identified key regulators of ectopic calcification. Based on the pathogenic principles causing the diseases, these can be classified into three groups: (1) disorders of an increased extracellular inorganic phosphate/inorganic pyrophosphate ratio (generalized arterial calcification of infancy, pseudoxanthoma elasticum, arterial calcification and distal joint calcification, progeria, idiopathic basal ganglia calcification, and hyperphosphatemic familial tumoral calcinosis; (2) interferonopathies (Singleton-Merten syndrome); and (3) others, including Keutel syndrome and Gaucher disease type IIIC. Although some of the identified causative mechanisms are not easy to target for treatment, it has become clear that a disturbed serum phosphate/pyrophosphate ratio is a major force triggering arterial and cardiac valve calcification. Further studies will focus on targeting the phosphate/pyrophosphate ratio to effectively prevent and treat these calcific disease phenotypes.

KCNH1 mutations have been identified in patients with Zimmermann-Laband syndrome and Temple-Baraitser syndrome, as well as patients with uncharacterized syndromes with intellectual disability and overlapping features. These syndromes include dysmorphic facial features, nail hypo/aplasia, thumb and skeletal anomalies, intellectual disability, and seizures. We report the epilepsy phenotype in patients with KCNH1 mutations. Demographic data, electroclinical features, response to antiepileptic drugs, and results of significant diagnostic investigations of nine patients carrying mutations in KCNH1 were obtained from referring centres. Epilepsy was present in 7/9 patients. Both generalized and focal tonic-clonic seizures were observed. Complete seizure control was achieved with pharmacological treatment in 2/7 patients; polytherapy was required in 4/7 patients. Status epilepticus occurred in 4/7 patients. EEG showed a diffusely slow background in 7/7 patients with epilepsy, with variable epileptiform abnormalities. Cerebral folate deficiency and an increase in urinary hypoxanthine and uridine were observed in one patient. Epilepsy is a key phenotypic feature in most individuals with KCNH1-related syndromes, suggesting a direct role of KCNH1 in epileptogenesis, although the underlying mechanism is not understood.

Schinzel-Giedion syndrome is a rare recognizable malformation syndrome defined by characteristic facial features, profound developmental delay, severe growth failure, and multiple congenital anomalies. The causative gene of Schinzel-Giedion syndrome, SETBP1, has been identified, but limited cases have been confirmed by molecular analysis. We present a 9-month-old girl affected by West syndrome with Schinzel-Giedion syndrome. Congenital severe hydronephrosis, typical facial features, and multiple anomalies suggested a clinical diagnosis of Schinzel-Giedion syndrome. Hypsarrhythmia occurred at 7 months of age and was temporarily controlled by adrenocorticotropic hormone (ACTH) therapy during 5 weeks. SETBP1 mutational analysis showed the presence of a recurrent mutation, p.Ile871Thr. The implications in management of Schinzel-Giedion syndrome are discussed., (© The Author(s) 2014.)

Background: Camptodactyly is usually painless, not caused by trauma, often appearing bilaterally, gradually progressive flexion contracture of the proximal interphalangeal joint mainly on the 5th fingers., Objectives: The aim of the study was to analyze the efficacy injecting botulinum neurotoxin in short muscles of the hand responsible for the contraction of the proximal interphalangeal joint., Material and Methods: The clinical material consisted of 12 patients (8 women, 4 men) treated with injections of botulinum neurotoxin in 2009-2012. Patients were monitored respectively for 2 weeks, 3 and 6 months and then every six months after the procedure. The observation period after injection of toxin ranged from 18 to 36 months. Our proposed method of treatment is inducing a temporary paralysis of muscles (lumbrical, interosseous) by means of botulinum neurotoxin (Botox)., Results: In the majority (10) of patients an improvement and stabilization was achieved just after one injection and there were no disease progression in subsequent controlled studies. These patients continued treatment with usage of redressing extensive splints. In case of the other two patients it was required to repeat the injections., Conclusions: The preliminary results obtained are promising. This method of treatment requires further studies and long-term follow-ups every six months until release of symptoms of the disease will be achieved. The operative treatment is reserved for severe deformities.

Myhre syndrome is a rare disorder characterized by pre- and postnatal short stature, brachydactyly, facial dysmorphism (short palpebral fissures, maxillary hypoplasia, prognathism and short philtrum), thick skin, muscular-appearing body build, decreased joint mobility, mixed hearing loss, and cleft lip and palate. Other clinical features include skeletal dysplasia, developmental delay with intellectual disability and/or behavioral disturbance, cardiac defects, cryptorchidism, and bone anomalies. The disease is caused by recently identified SMAD4 mutations. Here we describe a 7-year-old boy with a molecularly proven Myhre syndrome who presented life-threatening recurrent pericarditis and systemic inflammatory symptoms that required treatment with steroid and recombinant interleukin-1 receptor antagonist., (Copyright © 2013 Wiley Periodicals, Inc.)

Gordon's syndrome is a rare autosomal dominant disease that manifests in childhood. It is characterized by hypertension, hyperkalemic hyperchloremic metabolic acidosis, low renin and usually normal aldosterone levels, and it is sensitive to thiazide diuretics. A 20-year-old male with a history of diagnosed Gordon's syndrome was referred to a nephrology clinic for evaluation. The patient, who was under treatment with hydrochlorothiazide, had been diagnosed with Gordon's syndrome at the age of 11, when he presented hypertension and episodes of hyperkalemic hyperchloremic metabolic acidosis. However, none of his relatives had been diagnosed with this syndrome. Therefore, we assume that our patient might be a case of de novo gene mutation.

Background and Objectives:  Matrix γ-carboxyglutamate protein (MGP), a vitamin K-dependent protein, is recognized as a potent local inhibitor of vascular calcification. Studying patients with Keutel syndrome (KS), a rare autosomal recessive disorder resulting from MGP mutations, provides an opportunity to investigate the functions of MGP. The purpose of this study was (i) to investigate the phenotype and the underlying MGP mutation of a newly identified KS patient, and (ii) to investigate MGP species and the effect of vitamin K supplements in KS patients., Methods:  The phenotype of a newly identified KS patient was characterized with specific attention to signs of vascular calcification. Genetic analysis of the MGP gene was performed. Circulating MGP species were quantified and the effect of vitamin K supplements on MGP carboxylation was studied. Finally, we performed immunohistochemical staining of tissues of the first KS patient originally described focusing on MGP species., Results:  We describe a novel homozygous MGP mutation (c.61+1G>A) in a newly identified KS patient. No signs of arterial calcification were found, in contrast to findings in MGP knockout mice. This patient is the first in whom circulating MGP species have been characterized, showing a high level of phosphorylated MGP and a low level of carboxylated MGP. Contrary to expectations, vitamin K supplements did not improve the circulating carboxylated mgp levels. phosphorylated mgp was also found to be present in the first ks patient originally described., Conclusions:  Investigation of the phenotype and MGP species in the circulation and tissues of KS patients contributes to our understanding of MGP functions and to further elucidation of the difference in arterial phenotype between MGP-deficient mice and humans., (© 2011 International Society on Thrombosis and Haemostasis.)

Vohwinkel syndrome (mutilating and diffuse palmoplantar keratoderma) is associated with various extracutaneous features including icthyosis and deafness. Its mode of inheritance is autosomal dominant with mutation in loricrin and Connexin 26 genes. Here we report a mutilating and focal palmoplantar keratoderma in two siblings with congenital hypotrichosis and probably autosomal recessive inheritance that appears to be a new variant of Vohwinkel syndrome.