Hypertension in Potocki-Shaffer syndrome: A case report.

Potocki-Shaffer syndrome (PSS) is a rare contiguous gene deletion syndrome caused by heterozygous deletion of 11p11.2p12. Typical features described in patients with PSS include developmental delay, intellectual disability, multiple cartilaginous exostoses, biparietal foramina, craniofacial abnormalities, and genitourinary anomalies. While hypertension has been noted in three patients with PSS, it has not been described in most patients with this syndrome. This report details the evaluation and treatment of a teenager with PSS who presented on several occasions during childhood with elevated blood pressure measurements. The renin level was elevated, likely indicating a secondary cause for the HTN. The patient's BP responded to monotherapy with Angiotensin Converting Enzyme Inhibitor (ACEI).

A Novel EXT1 Mutation Identified in a Family with Multiple Osteochondromas.

AIMS: Multiple exostoses (MO), also referred to as hereditary multiple exostoses (HME), is an autosomal dominant inherited skeletal disorder that has been found to be associated with mutations in the EXT1 and EXT2 genes. In the present study, we report a Chinese family with HME and our mutational analyses of the EXT1 and EXT2 genes in affected and unaffected individuals. METHODS: All exons of the EXT1 and EXT2 genes in seven family members were polymerase chain reaction amplified from blood and sequenced. RESULTS: A heterozygous mutation (c.1056G>T) was identified in exon 2 of the EXT1 gene in the proband and other affected family members; this mutation was not found in the unaffected family members. DISCUSSION: This c.1056G>T mutation is located in the exostosin domain of the EXT1 protein and leads to an amino acid change of Glutamine (Gln) to Histidine (His) at position 352. Homology searches reveal that Gln352 is highly conserved in many species and may play an essential role in the normal function of the EXT1 protein. CONCLUSIONS: This study contributes to a better understanding of the genetic basis of HME, expands the known mutational spectrum of EXT1, and provides a reference for genetic counseling and prenatal diagnosis of this family.

Rhabdomyolysis in Stuve-Wiedemann syndrome.

A 6-month-old male infant with Stuve-Wiedemann syndrome (SWS) presented with an acute respiratory arrest secondary to a rhinovirus respiratory infection from which he was rapidly resuscitated. He developed an acute kidney injury requiring supportive treatment and on day 3 of his illness was noted to have developed severe rhabdomyolysis (creatine kinase level 132 040 U/L (normal <320 U/L)). He was born from consanguineous parents with homozygous mutations in the leukaemia inhibitory factor receptor. He had skeletal dysplasia with metabolic bone disease and episodes of hyperthermia with lactic acidosis. He also had paroxysmal ventricular tachycardia treated with prophylactic propranolol. This is a case report of a child with SWS who had a febrile illness and epileptic seizures which led to severe rhabdomyolysis outside the context of anaesthesia, and we would like to draw the attention of clinicians to this potential complication.

Glycosaminoglycans in the blood of hereditary multiple exostoses patients: Half reduction of heparan sulfate to chondroitin sulfate ratio and the possible diagnostic application.

Hereditary multiple exostoses (HME) is an autosomal dominant skeletal disorder with wide variation in clinical phenotype and is caused by heterogeneous germline mutations in two of the Ext genes, EXT-1 and EXT-2, which encode ubiquitously expressed glycosyltransferases involved in the polymerization of heparan sulfate (HS) chains. To examine whether the Ext mutation could affect HS structures and amounts in HME patients being heterozygous for the Ext genes, we collected blood from patients and healthy individuals, separated it into plasma and cellular fractions and then isolated glycosaminoglycans (GAGs) from those fractions. A newly established method consisting of a combination of selective ethanol precipitation of GAGs, digestion of GAGs recovered on the filter-cup by direct addition of heparitinase or chondroitinase reaction solution and subsequent high-performance liquid chromatography of the unsaturated disaccharide products enabled the analysis using the least amount of blood (200 µL). We found that HS structures of HME patients were almost similar to those of controls in both plasma and cellular fractions. However, interestingly, although both the amounts of HS and chondroitin sulfate (CS) varied depending on the different individuals, the amounts of HS in both the plasma and cellular fractions of HME patient samples were decreased and the ratios of HS to CS (HS/CS) of HME patient samples were almost half those of healthy individuals. The results suggest that HME patients' blood exhibited reduced HS amounts and HS/CS ratios, which could be used as a diagnostic biomarker for HME.

Anemia in children with cartilage-hair hypoplasia is related to body growth and to the insulin-like growth factor system.

Cartilage-hair hypoplasia (CHH) is a metaphyseal chondrodysplasia characterized by severe short-limbed short stature, hypoplastic hair, and defective immunity. The patients also have anemia. As GH may regulate both body growth and erythropoiesis, we used CHH as a clinical model to study their interrelationships. Retrospective analysis of hematological data of 114 patients showed that the severity of the anemia and macrocytosis in CHH varies with age. The anemia was most severe in early childhood. A prospective study of 21 patients with CHH showed that height correlates with hemoglobin (P = 0.006) and mean corpuscular volume of red blood cells (P < 0.0001). The individual hemoglobin levels correlated with the GH parameters [P = 0.035 for insulin-like growth factor I (IGF-I) and P = 0.002 for IGF-binding protein-3], and the mean corpuscular volume of red blood cell values correlated with fetal hemoglobin. Bone marrow cultures obtained from six patients with CHH showed reduced or totally absent erythroid colony formation, which was not influenced by GH or IGF-I in vitro or by GH treatment in vivo. In patients with CHH, we observed an association between erythropoiesis and growth. We conclude that body growth and erythropoiesis share common regulators. One of these is the GH-IGF-I axis; other factors, as not yet identified, may also be important.

Coexistence of hereditary multiple exostoses and ankylosing spondylitis.

We report a 50-year-old male patient with hereditary multiple exostoses (HME) and ankylosing spondylitis (AS). This is the first case reporting the coexistence of HME and AS. Our patient has multiple exostoses around the knee, elbow and wrist joints. At the age of 40 years, pain in the lower back associated with morning stiffness lasting about an hour and improving with exercise began. His son also has hereditary multiple exostoses but has no sign of AS. HME is an autosomal dominant disorder. AS has a remarkably strong association with the histocompatibility antigen HLA-B27. Owing to the different genetic mechanisms, it is not possible to differentiate between coincidence and association. Coexistence of HME and AS in our patient probably represents a coincidence rather than a real association.