PICO questions and DELPHI methodology for improving the management of patients with acute hepatic porphyria.

BACKGROUND: Acute hepatic porphyrias (AHPs) are a group of rare diseases that encompasses acute intermittent porphyria, variegate porphyria, hereditary coproporphyria, and 5-aminolaevulinic acid dehydratase deficiency porphyria. Symptoms of AHP are nonspecific which, together with its low prevalence, difficult the diagnosis and follow-up of these patients. MATERIAL AND METHODS: This project used DELPHI methodology to answer PICO questions related to management of patients with AHPs. The objective was to reach a consensus among multidisciplinary porhyria experts providing answers to those PICO questions for improving diagnosis and follow-up of patients with AHP. RESULTS: Ten PICO questions were defined and grouped in four domains: 1. Biochemical diagnosis of patients with AHP. 2. Molecular tests for patients with AHP. 3. Follow-up of patients with AHP. 4. Screening for long-term complications of patients with AHP. CONCLUSIONS: PICO questions and DELPHI methodology have provided a consensus on relevant and controversial issues for improving the management of patients with AHP.

The c.859G>C variant in the SMN2 gene is associated with types II and III SMA and originates from a common ancestor.

Homozygous mutations of the telomeric SMN1 gene lead to degeneration of motor neurons causing spinal muscular atrophy (SMA). A highly similar centromeric gene (SMN2) can only partially compensate for SMN1 deficiency. The c.859G>C variant in SMN2 has been recently reported as a positive disease modifier. We identified the variant in 10 unrelated chronic SMA patients with a wide spectrum of phenotypes ranging from type II patients who can only sit to adult walkers. Haplotype analysis strongly suggests that the variant originated from a common ancestor. Our results confirm that the c.859G>C variant is a milder SMN2 allele and predict a direct correlation between SMN activity and phenotypic severity.

[Review of 22 patients with 22q11.2 deletion syndrome: phenotype spectrum]. / Revisión de 22 casos de deleción 22q11.2: espectro fenotípico.

INTRODUCTION: The 22q11.2 deletion syndrome is a contiguous gene deletion syndrome with an incidence rate of 1/4,000-6,000 live births. The most specific clinical features are: congenital conotruncal heart diseases, palate anomalies, hypocalcaemia, immunity and learning problems, and a characteristic facial phenotype. The objective of this work is to review the presenting phenotype and clinical features of children with 22q11.2 deletion syndrome as a guide for early diagnosis. PATIENTS AND METHODS: Retrospective study of 22 patients with 22q11.2 deletion syndrome diagnosed at our hospital in the time period 2004-2007. Variables analyzed: incidence, sex, age at diagnosis, presenting phenotype, clinical features, positive family history, mortality and natural history. RESULTS: From a total of 22 patients, 63 % were males, and the median age at diagnosis was of 4.5 years. Presenting pheno-type: congenital heart disease, milestones delay, velopharyngeal incompetence, hypocalcaemia, and mental retardation/psychiatric disturbances. CLINICAL FEATURES: congenital heart disease (84 %), velopharyngeal incompetence (47 %), milestones delay and learning disabilities (79 %). All of the deletions were de novo, except in one case where the deletion was present as mosaicism in the father. Three patients died, due to congenital heart disease. CONCLUSIONS: Clinical expression is widely variable, although a characteristic phenotype exists. Patients with heart disease are diagnosed earlier than other patients with unusual presenting phenotype such as congenital dysphagia. It is important to recognize less common phenotypes at early ages in order to provide multidisciplinary monitoring and accurate genetic counselling.

Duplication 19q13-qter and deletion 19p13-pter arising from an inversion (19)(p13.3q13.3) of maternal origin.

Pericentric inversion of chromosome 19 appears to be a rare abnormality with only a few families reported. As far as we are aware, none of them were ascertained because of a recombinant individual. We describe the first identified case due to an affected patient, with duplication deficiency for chromosome 19 arising from a maternal inversion confirmed by FISH and CGH. His features included prenatal growth retardation, microcephaly, dysmorphic facies, congenital heart defect, hypoplasia of corpus callosum and psychomotor delay. The identification of recombinant individuals contribute to calculate a precise risk for inv (19) carriers and to provide a more accurate genetic counselling.

[Schinzel-Giedion syndrome: a new mutation in SETBP1]. / Síndrome Schinzel-Giedion: nueva mutación en SETBP1.

Schinzel-Giedion syndrome (SGS) (#MIM 269150) is a rare genetic disorder characterized by very marked craniofacial dysmorphism, multiple congenital anomalies and severe intellectual disability. Most affected patients die in early childhood. SETBP1 was identified as the causative gene, but a limited number of patients with molecular confirmation have been reported to date. The case is reported of a 4 and a half year-old male patient, affected by SGS. SETBP1 sequencing analysis revealed the presence of a non-previously described mutation: c.2608G>T (p.Gly870Cys). The clinical features and differential diagnosis of this rare condition are reviewed. Dysmorphic features are strongly suggestive of SGS. Its clinical recognition is essential to enable an early diagnosis, a proper follow-up, and to provide the family with genetic counseling. To date, this is the seventeenth SGS patient published with SETBP1 mutation, and the first in Spain, helping to widen clinical and molecular knowledge of the disease.

Mendelian diseases among Roman Jews: implications for the origins of disease alleles.

The Roman Jewish community has been historically continuous in Rome since pre-Christian times and may have been progenitor to the Ashkenazi Jewish community. Despite a history of endogamy over the past 2000 yr, the historical record suggests that there was admixture with Ashkenazi and Sephardic Jews during the Middle Ages. To determine whether Roman and Ashkenazi Jews shared common signature mutations, we tested a group of 107 Roman Jews, representing 176 haploid sets of chromosomes. No mutations were found for Bloom syndrome, BRCA1, BRCA2, Canavan disease, Fanconi anemia complementation group C, or Tay-Sachs disease. Two unrelated individuals were positive for the 3849 + 10C->T cystic fibrosis mutation; one carried the N370S Gaucher disease mutation, and one carried the connexin 26 167delT mutation. Each of these was shown to be associated with the same haplotype of tightly linked microsatellite markers as that found among Ashkenazi Jews. In addition, 14 individuals had mutations in the familial Mediterranean fever gene and three unrelated individuals carried the factor XI type III mutation previously observed exclusively among Ashkenazi Jews. These findings suggest that the Gaucher, connexin 26, and familial Mediterranean fever mutations are over 2000 yr old, that the cystic fibrosis 3849 + 10kb C->T and factor XI type III mutations had a common origin in Ashkenazi and Roman Jews, and that other mutations prevalent among Ashkenazi Jews are of more recent origin.

Biliary duct injury: partial segment IV resection for intrahepatic reconstruction of biliary lesions.

A technique for intrahepatic reconstruction of the biliary tree after complex high injuries is described. The fundament of the procedure is the removal of a wedge of segment IV at the level of the hilar plate. When the hilar plate is reached and no adequate exposure of the ducts can be obtained, removing a 1 x 1-in wedge of segment IV between the gallbladder bed and the round ligament exposes the left and right ducts. An anteroposterior view of the plate is obtained instead of a caudocephalic dissection, exposing healthy, nonscarred ducts for reconstruction. We have used this approach in 22 patients, and adequate exposure of the ducts has been obtained, with a high success rate of patency of the anastomosis at a mean follow-up of 3 years. Twenty patients have a patent anastomosis, with a good quality of life and no restenosis.

Small-diameter mesocaval shunts: a 10-year evaluation.

The use of small-diameter portosystemic shunts for the treatment of bleeding esophageal varices caused by portal hypertension has emerged as an outgrowth of the development of polytetrafluoroethylene vascular grafts, which allow the use of a narrow lumen. We report our experience with this type of graft over a 10-year period. Thirty-three patients with good liver function (Child-Pugh class A) were electively operated. The average age of these patients was 45 years (range 17 to 71 years). Twenty-nine patients had liver cirrhosis, one had portal fibrosis, and three had idiopathic portal hypertension. Operative mortality was 3%, and the rebleeding rate was 15%. Postoperative encephalopathy was observed in 14 patients (11%), three of whom had grade III to IV encephalopathy. The remaining 11 patients, had mild encephalopathy that was easily controlled. Postoperative angiography showed shunt patency in 81% of the patients, reduction in portal vein diameter in 33% of the patients, and portal vein thrombosis in 6%. Good postoperative quality of life was observed in 63% of the patients. Survival according to the Kaplan-Meier actuarial method was 81% at 12 months, 56% at 60 months, and 36% at 10 years. These shunts are a good alternative for patients being considered for surgery in whom other portal blood flow preserving procedures (i.e., elective shunts, devascularization with esophageal transection) are not feasible.

A new form of complicated hereditary spastic paraplegia with cataracts, atretic ear canals and hypopigmentation.

A 16-year-old Hispanic boy born of consanguineous parents is described as having a history of cataracts, progressive lower-extremity spasticity and atrophy starting at 4 years of age, atretic ear canals with hearing dysfunction and diffuse patchy cutaneous hypopigmented areas. Clinical examination showed the typical signs of spastic paraplegia with increased tone, hyperreflexia, muscle atrophy and contractures. Sensation, autonomic and cerebellar functions were not disturbed. Neuroimaging studies were normal. Laboratory findings did not support a diagnosis of metabolic disturbance or infectious disease. This is considered a new form of complicated hereditary spastic paraplegia (HSP), transmitted presumably in an autosomal recessive pattern.

Acro-renal-ocular syndrome: expansion of the phenotype.

We report the sixth described family with acro-renal-ocular syndrome in a boy and more mildy in his mother. Severe upper limb deficiency, dysplastic kidneys, and strabismus are noted in this child in addition to developmental delay, dysplastic corpus callosum, and incomplete myelination. Developmental central nervous system (CNS) malformations have not been described in this syndrome previously and may represent an expansion of the phenotype.

A compound heterozygous mutation in the EDAR gene in a Spanish family with autosomal recessive hypohidrotic ectodermal dysplasia.

Hypohidrotic ectodermal dysplasia (HED) is a genetic disorder characterised by sparse hair, lack of sweat glands and malformation of teeth. The X-linked form of the disease, caused by mutations in the EDA gene, represents the majority of HED cases. Autosomal forms result from mutations in either the EDAR or the EDARADD gene. The X-linked and autosomal forms are phenotypically indistinguishable. For the purpose of genetic counselling, it is, therefore, important to know which gene is involved. In this study, we ascertained a Spanish family demonstrating the autosomal recessive form of HED. Affected individuals in the family showed the characteristic features of HED, including fine and sparse scalp hair, sparse eyebrows and eyelashes, periorbital hyperpigmentation, prominent lips, hypodontia and conical teeth, reduced sweating, and dry and thin skin. Sequence analysis of the EDAR gene revealed a novel compound heterozygous mutation [c.52-2A>G; c.212G>A (p.Cys71Tyr)]. Our finding extends the body of evidence that supports the significance of the EDAR signalling pathway in the ectodermal morphogenesis.

[Fragile X syndrome]. / Síndrome X frágil.

INTRODUCTION AND DEVELOPMENT: Fragile X syndrome is the main inheritable genetic cause of mental retardation. It is a dynamic mutation and is due to the increase in the number of CGG triplets in exon 1 of the FMR1 gene, located in Xq27.3, and to the hypermethylation of the corresponding genomic region, which impedes production of messenger RNA and, therefore, of FMRP protein. Three types of alleles can be established, according to the number of repetitions: normal, with premutation and with full mutation. Only individuals with full mutation have fragile X syndrome. Two sub-phenotypes of the syndrome, associated to premutation, have recently been reported and are seen to appear from the fourth decade of life onwards. CONCLUSIONS: The number of female carriers of a premutation with early ovarian failure has increased, while reports have also appeared describing a neurological picture of intentional trembling and ataxia among carriers of the premutation (FXTAS).

[Monogenic causes of X-linked mental retardation]. / Causas monogénicas de retraso mental ligado a X.

INTRODUCTION AND DEVELOPMENT: The term X-linked mental retardation (XLMR) refers to a heterogeneous group of conditions that, on the basis of their presenting symptoms, have traditionally been classified as being syndromic (SMR) and non-syndromic or non-specific (XMR). The prevalence of XLMR in males is estimated to be 10%, excluding fragile X syndrome, which is the most common monogenic cause. There are over 100 genes involved in XLMR. In this work we review some of the phenotypes and genes involved in SMR. A small stature and coarse features indicate a suspected case of Coffin-Lowry syndrome, which is secondary to mutations of the RPS6KA3 or RSK2 genes. Cerebellar hypoplasia points towards alterations of the OPHN1 gene. In males with coarse features and genital abnormalities screening for alpha thalassemia must be carried out; this association results from mutations in the ATRX gene. Of the genes involved in mental retardation and epilepsy, the most notable are SLC6A8 (which triggers a deficit in creatine transport when altered and which is easily detected with respect to its biochemistry) and ARX (also associated to lissencephaly and dystonia of the hands). Mutations in the PQBP1 and JARID1C genes have been identified in patients with mental retardation associated to microcephaly and short stature. A high level of T3 hormone points towards defects in the SLC16A2 gene. Some of these genes have also been implicated in XMR, which makes this distinction less clear molecularly speaking. CONCLUSIONS: Systematic screening of all the genes involved in XLMR is not possible in clinical praxis today. It is important to search for differential phenotypic features in males with mental retardation that guide the study towards specific genes. Identification of the molecular defect will allow for correct genetic counselling. DNA microarrays for the study of different mutations in a large number of genes involved in mental retardation are the great hope for the future.