Adrenocortical nodular hyperplasia as a cause of Cushing syndrome in the neonatal period]

The case report of a female child born preterm (30th wk of gestation) who developed symptoms of Cushing's syndrome beginning in the neonatal phase is presented. The disease was caused by a unilateral adreno-cortical nodular hyperplasia and was successfully treated by unilateral adrenalectomy. Preoperative treatment with ketoconazole and metyrapone proved to be effective. Symptoms of Cushing's disease including hypertrophic cardiomyopathy were completely reversible within one month after surgery.     

IRS1 and GRB2 as members of the IGF signal transduction pathway are not associated with intrauterine growth retardation and Silver-Russell syndrome

We report a familial deletion of (8q) detected in amniocytes of a fetus with a normal ultrasound and in the phenotypically normal mother, who has now had three pregnancy losses. Chromosome analysis of amniocytes and maternal peripheral blood cells showed an interstitial deletion of (8)(q24.13q24.22), which is distal to the region associated with Langer-Giedion syndrome (LGS) or trichorhinophalangeal (TRP) syndrome. This deletion was confirmed by fluorescence in situ hybridization with a c-myc cosmid clone and chromosome 8 painting library.     

Transport, enzymatic activity, and stability of mutant sulfamidase (SGSH) identified in patients with mucopolysaccharidosis type III A

Mucopolysaccharidosis type IIIA (MPSIIIA) is an autosomal recessive lysosomal storage disease caused by mutations in the N-sulfoglucosamine sulfohydrolase gene (SGSH; encoding sulfamidase, also sulphamidase) leading to the lysosomal accumulation and urinary excretion of heparan sulfate. Considerable variation in the onset and severity of the clinical phenotype is observed. We report here on expression studies of four novel mutations: c.318C>A (p.Ser106Arg), c.488T>C (p.Leu163Pro), c.571G>A (p.Gly191Arg), and c.1207_1209delTAC (p.Tyr403del), and five previously known mutations: c.220C>T (p.Arg74Cys), c.697C>T (p.Arg233X), c.1297C>T (p.Arg433Trp), c.1026dupC (p.Leu343fsX158), and c.1135delG (p.Val379fsX33) identified in MPSIIIA patients. Transient expression of mutant sulfamidases in BHK or CHO cells revealed that all the mutants were enzymatically inactive with the exception of c.318C>A (p.Ser106Arg), which showed 3.3% activity of the expressed wild-type enzyme. Western blot analysis demonstrated that the amounts of expressed mutant sulfamidases were significantly reduced compared with cells expressing wild type. No polypeptides were immunodetectable in extracts of cells transfected with the cDNA carrying the c.697C>T (p.Arg233X) nonsense mutation. In vitro translation and pulse-chase experiments showed that rapid degradation rather than a decrease in synthesis is responsible for the low, steady-state level of the mutant proteins in cells. The amounts of secreted mutant precursor forms, the cellular stability, the proteolytic processing, and data from double-label immunofluorescence microscopy suggest that the degradation of the majority of newly synthesized c.220C>T (p.Arg74Cys), c.571G>A (p.Gly191Arg), c.1297C>T (p.Arg433Trp), c.1026dupC (p.Leu343fsX158), and c.1135delG (p.Val379fsX33) mutant proteins probably occurs in the ER, whereas c.488T>C (p.Leu163Pro) mutant protein showed instability in the lysosomes.     

Paternally inherited deletion of CSH1 in a patient with Silver-Russell syndrome.

In a continuing study on the aetiology of Silver-Russell syndrome (SRS), we detected a patient with a heterozygous deletion in the growth hormone gene cluster (17q22-q24). The deletion of the chorionic somatomammotrophin hormone 1 (CSH1) gene was inherited from the patient's father. The patient shows typical symptoms of SRS. Though deletions of CSH1 have been reported without any phenotypic consequences, the heterozygous deletion might be involved in the aetiology of SRS in the case presented here. Apart from other observations in SRS, like maternal uniparental disomy 7, changes in the genomic region 17q22-qter might be responsible for the expression of this syndrome for at least some of the patients, leading to the heterogeneity of SRS.     

Late denervation in patients with antecedent paralytic poliomyelitis

The development of new weakness, fatigue, and pain decades after acute paralytic poliomyelitis is a recognized syndrome. We conducted a controlled study of this syndrome by analyzing clinical, electromyographic, and muscle-biopsy features in 18 patients with a history of poliomyelitis--13 reporting 1 to 20 years of new weakness and 5 without new symptoms. The patients with new weakness also reported new muscle atrophy (9 of 13) and fatigue (10 of 13), symptoms not reported by the controls. The age at the time of acute poliomyelitis, severity of poliomyelitis, residual disability, number of years since acute poliomyelitis, and age at the time of study were comparable in the weakening and control groups. Evidence of remote denervation consistent with antecedent poliomyelitis was demonstrated in all patients by electromyography or muscle biopsy or both. In addition, active denervation (as evidenced by spontaneous activity on conventional electromyography, increased jitter on single-fiber electromyography, or atrophic myofibers) was found in 12 patients in the weakening group and in all 5 controls. Immunohistochemical detection of myofibers expressing the neural-cell adhesion molecule corroborated ongoing denervation in both patient groups. When muscle data from both groups were pooled, correlations were observed between the extent of past reinnervation and the degree of ongoing motor-unit instability. We conclude that the extensive reinnervation of denervated muscle that occurs in paralytic poliomyelitis may be followed by late denervation of the previously reinnervated muscle fibers. Electromyographic and muscle-biopsy evidence of ongoing denervation does not distinguish between stable patients with prior paralytic poliomyelitis and those with new weakness.     

The centromeric 11p15 imprinting centre is also involved in Silver-Russell syndrome

Silver-Russell syndrome (SRS) is a heterogeneous disorder characterised by severe intrauterine and postnatal growth retardation, limb and body asymmetry, a typical facial appearance and less common dysmorphisms. Recently, epimutations and maternal duplications affecting the short arm of chromosome 11 have been shown to have a crucial role in the aetiology of the disease. Disturbances in the same genomic region cause the overgrowth disorder Beckwith-Wiedemann syndrome (BWS). In BWS, mutations in the telomeric as well as in the centromeric imprinting centres (ICR1 and ICR2) in 11p15 can be observed. In SRS, methylation defects in the imprinted region in 11p15 were considered to be restricted to the telomeric ICR1. They can be detected in about 30% of patients. This article reports on the first patient with SRS with a cryptic duplication restricted to the centromeric ICR2 domain in 11p15. The maternally inherited duplication in this patient included a region of 0.76-1 Mbp and affected the genes regulated by the ICR2, among them CDKN1C and LIT1. This study provides evidence for a role for this imprinting centre in the aetiology of SRS and shows that SRS presents a picture genetically opposite to that of BWS.