Antenatal diagnosis of recessive dystrophic epidermolysis bullosa: collagenase expression in cultured fibroblasts as a biochemical marker.

We performed fetoscopy and skin biopsy on a 19-week fetus at risk for recessive dystrophic epidermolysis bullosa (RDEB). Ultrastructural analysis of the tissue revealed dermolytic blister formation in the skin characteristic of the disease. To develop a biochemical test for use in antenatal diagnosis of RDEB, we established skin fibroblast cultures from the 20-week aborted fetus. The collagenase production by fetal RDEB fibroblast cultures was greater than seen in normal fetal fibroblast cultures. The concentration in culture medium from fetal RDEB cultures was 5.42 +/- 0.74 micrograms/ml (mean +/- SE) compared with 2.24 +/- 1.11 micrograms/ml in normal adult control cultures and 2.05 +/- 0.61 micrograms/ml in cultures from patients with other genetic forms of epidermolysis bullosa (p less than 0.025). In contrast, the concentration of collagenase in the fetal RDEB culture medium was not different from that seen in cell cultures from known patients with RDEB (5.34 +/- 1.12 micrograms/ml). Collagenase activity of the fetal RDEB medium was also increased approximately 3.5-fold. These data indicate that enhanced expression of collagenase by fetal RDEB skin fibroblasts can serve as a biochemical adjunct, and possibly an alternative, to morphologic examination of tissue for antenatal diagnosis.

A case-control study of fluctuating dermatoglyphic asymmetry as a risk marker for developmental delay.

In traits which are normally bilaterally symmetrical, asymmetries may arise as a result of genomic or environmental stress. Such asymmetries are called fluctuating asymmetry. Symmetry is known to be decreased in a variety of disorders of developmental origin, and thus could potentially serve as a risk marker for disorders with a developmental component. We examined this idea by conducting a case-control study of 49 developmentally delayed children and 51 controls. Using two dermatoglyphic characters as a measure of symmetry (finger print concordance and A-B triradial ridge count difference), we found odds ratios of 2.32 (95% CI 0.65-3.17) and 2.11 (95% CI 0.57-3.27); depending on which character was measured. These results suggest that fluctuating asymmetry may have potential as a risk marker for developmental disorders, and that this area of research warrants further research.

Fluctuating asymmetry and disorders of developmental origin.

Environmental and/or genetic stresses may cause a breakdown in developmental homeostasis, resulting in increased bilateral asymmetry of morphological traits. The degree of these deviations (termed "fluctuating asymmetry") is thought to correlate with the severity of the stress. If these stresses also play a role in the appearance of developmental disorders, then increased morphological asymmetry may serve as a risk marker for disorders of developmental origin. This would be possible if 1) the environmental stress that caused a breakdown in developmental stability also contributed to the appearance of the disorder, and/or 2) the genetic predisposition (liability) to the disorder and increased susceptibility to fluctuating asymmetry have a common cause. Although a number of authors have reported associations between increased fluctuating asymmetry and disorders of presumed developmental origin, the usefulness of fluctuating asymmetry as a risk marker has not been established. One obstacle to this assessment is the lack of odds ratios reported by previous authors.

GMS syndrome: a new dominant condition with goniodysgenesis, mental retardation, and short stature.

We describe a mother and daughter with a distinct phenotype that is different from previous reports. This is likely to constitute a new syndrome for which we propose the mnemonic GMS for G goniodysgenesis, M mental deficiency, and S short stature. The pattern of occurrence is compatible with either autosomal dominant or X-linked inheritance.

Schimke immuno-osseous dysplasia: case report and review.

We report on a patient with Schimke immunoosseous dysplasia, an autosomal recessive disorder, and review nine patients from the literature. Manifestations include spondyloepiphyseal dysplasia, lymphopenia, signs of defective cellular immunity, and progressive renal disease. This is the first patient known to have the additional findings of thrombocytopenia and microdontia.

Hypomandibular faciocranial dysostosis: another case and review.

We report on a third case of hypomandibular faciocranial dysostosis and review the literature. Manifestations include craniosynostosis, prominent eyes, deficient midface and zygomatic arches, short nose with anteverted nares, protruding lower face, minute oral aperture, persistent buccopharyngeal membrane, and severe mandibular hypoplasia. In contrast to coronal synostosis found in the 2 earlier cases, our patient had multiple sutural synostosis. The 2 affected sibs reported earlier suggest the possibility of autosomal recessive inheritance. However, gonadal mosaicism for a dominant mutation or an undetected microdeletion must also be considered at this early stage in the delineation of this disorder.

Mesomelic dysplasia with absence of fibulae and hexadactyly: Nievergelt syndrome or new syndrome?

Mesomelic dysplasia is a form of short-limb dwarfism characterized by disproportionate shortness of the middle segment of all limbs. Included in this category of skeletal disorders is the Nievergelt syndrome, which typically manifests a rhomboidal shape of the tibiae and fibulae, an unusual foot deformity, radioulnar synostosis, and dysplasia of the elbow and knee joints. We describe a patient with mesomelic dysplasia with findings suggestive of the Nievergelt syndrome and with absence of fibulae and hexadactyly.

Genealogy, natural history, and phenotype of Alström syndrome in a large Acadian kindred and three additional families.

We describe a large Acadian kindred including 8 Alstrom Syndrome (AS) patients, with an age range of 4 to 26 at the time of clinical assessment. The affected subjects come from 5 nuclear families within this kindred. The phenotype includes early childhood retinopathy, progressive sensorineural hearing loss, truncal obesity, and acanthosis nigricans. In addition, hyperinsulinemia and hypertriglyceridemia with normal cholesterol levels were observed in most affected individuals tested. Non-insulin dependent diabetes mellitus and growth retardation appear to be age-related manifestations that occur post-adolescence. Younger affected children are not overtly hyperglycemic and are normal or above average height for age. Although the AS patients in kindred 1 presumably carry the same mutation, many manifestations of the disease are variable. For example, of the 8 children in the Acadian kindred, 4 have scoliosis, 2 have had infantile cardiomyopathy, 2 are hypothyroid, 1 has had hepatic dysfunction and is hypertensive, and 4 have developed asthma. Seven subjects described in this kindred exhibit developmental delay. One additional manifestation not described widely in the literature, advanced bone age, was observed in all subjects tested. The clinical data from this large Acadian kindred, together with information obtained from 4 additional AS patients in 3 unrelated kindreds, confirm and extend clinical observations previously described. In addition, the Acadian kindred with multiple affected individuals, probably arising from a common founder, should allow for identification of the chromosomal localization of a gene causing AS.

Resting energy expenditure in Gaucher's disease type 1: effect of Gaucher's cell burden on energy requirements.

The resting energy expenditure (REE; kcal/d) of 25 patients with Gaucher's disease type 1 was determined by indirect calorimetry. The average observed REE for the group was approximately 44% greater (P less than .01) than that predicted (predicted REE) for these patient's age, sex, height, and weight. The increased caloric requirements of these patients was manifested by a height-for-age less than or equal to the fifth percentile in seven of nine growing children and a muscle mass of less than the fifth percentile in 15 of 19 patients studied. The excess REE (observed REE--predicted REE) for individual Gaucher's disease type 1 patients was directly related to their liver volume as estimated from radionuclide scans and to the mass of the spleen as measured at splenectomy. The relationship between spleen mass and excess REE was demonstrated by an average 22.0% decrease in REE following splenectomy in five patients. Based on these data, the metabolic rate of the splenic tissue removed from the patients was calculated to be 96.8 kcal/d/kg, about twofold to threefold less than that of normal splenic tissue. These findings indicate that the elevated REE observed in these patients resulted from the large mass of Gaucher's cells, which although individually hypometabolic, were cumulatively an excessive metabolic burden. Furthermore, they suggest that indirect calorimetry may be a quantitative tool for measuring disease progression and the effect of therapeutic intervention in Gaucher's disease type 1.

Longitudinal study of the early electroretinographic changes in Alström's syndrome.

We obtained serial electroretinograms in four patients aged between 6 months and 5 years with Alström's syndrome and studied the early stages of the severe retinopathy that is characteristic of that disease. The weak electroretinographic signals found at age 6 months demonstrate a severe early cone dysfunction; one year later the cone activity is undetectable. The rod component of the electroretinogram is initially normal but can rapidly deteriorate to become undetectable as early as 5 years of age. These unusual electroretinographic findings are pathognomonic of Alström's syndrome and different from other cone-rod dystrophies or other syndromes with similar phenotypes such as Bardet-Biedl, Laurence-Moon, and Cohen syndromes.

Successful treatment of painful crises of Fabry disease with low dose morphine.

Fabry disease is an X-linked disorder characterized in childhood by angiokeratoma, corneal opacities, and pain. At age 7 years our patient began experiencing an intermittent intense "burning" sensation within his feet and hands (acroparesthesias). Treatment with aspirin, acetaminophen, acetominophen with codeine, and phenytoin was unsuccessful. Carbamazepine and phenytoin reduced the frequency and duration of painful crises to 3-4 times annually. A treatment plan was developed consisting of a low-dose morphine infusion with increasing dosage until pain was relieved. Over the subsequent 28 months, we have had experienced treating 7 crises with morphine given as 0.06 mg/kg IV push, followed by a continuous infusion of 0.02 mg/kg/hr with amitriptyline 0.25 mg/kg at bedtime. Pain control is immediate, with the infusion gradually tapered after 24 hours.

Gaucher disease: fate of the splenic remnant after partial splenectomy--a case of rapid enlargement.

In Gaucher disease, partial splenectomy has been suggested for alleviating the complications of splenomegaly as well as for avoiding the immunologic compromise and potential acceleration of bony and hepatic involvement that may follow total splenic resection. However, the fate of the splenic remnant has been reported rarely. A subtotal splenectomy (85%) was performed in a 19-month-old girl with rapidly progressing Gaucher disease and massive splenomegaly (12% of body weight). Within 3 months, the splenic remnant had increased four-fold in size. Previous reports indicated only three Gaucher patients had significant enlargement of the splenic remnant after partial splenectomy. These findings indicate that splenomegaly may recur rapidly in Gaucher disease following partial splenectomy.

Glycosphingolipid studies of visceral tissues and brain from type 1 Gaucher disease variants.

Glucosylceramide and glucosylsphingosine isolated from spleen, liver and brain were quantitated and characterized in two unrelated patients with Gaucher disease, neither of whom had clinical or neuropathologic evidence of neuronal involvement. Visceral glucosylceramide accumulation did not differ in the two patients. Hepatic glucosylsphingosine content was 2-fold greater in a young severely affected 3-year-old American Black patient compared to that in a 56-year-old Ashkenazi Jewish patient. In contrast, significant differences in glycosphingolipid content and composition were observed in the brains of these two cases. Cerebral and cerebellar cortical glucosylceramide accumulated to a greater extent (3-fold) in the severely affected 3-year-old patient compared to that in the older case. The compositions of the acyl and sphingosyl base residues of glucosylceramide in the cerebral and cerebellar cortices from the Ashkenazi Jewish patient were similar to those in normal individuals. In comparison, the gray matter glucosylceramide in the severely affected patient had increased percentages of stearic acid (18:0) and eicosasphingenine (d20:1), suggesting that the accumulated substrate was derived from the brain ganglioside pool. Glucosylsphingosine was found in large amounts only in cerebral and cerebellar cortices from the severely affected patient. The glycolipid content and composition in this patient was similar to that found in the Norrbottnian (Type 3) form of Gaucher disease. The differences in glucosylceramide acyl and sphingosyl base composition in gray matter from the severely affected patient and that in the Ashkenazi Jewish patient suggested that the accumulated substrates were metabolized differently by the residual enzymes in each case.(ABSTRACT TRUNCATED AT 250 WORDS)

Human acid beta-glucosidase: Northern blot and S1 nuclease analysis of mRNA from HeLa cells and normal and Gaucher disease fibroblasts.

Human acid beta-glucosidase (beta-Glc) mRNA was evaluated by dot blot, Northern blot, and S1 nuclease analyses of extracts of HeLa cells and cultured fibroblasts from normal individuals and Gaucher disease patients. Dot blot quantitation indicated an equal concentration of specific mRNA in all sources. Northern blot analyses demonstrated the presence of three poly (A)+ mRNAs of about 5,600, 2,500, and 2,000 nucleotides in length from all cell extracts. All three mRNAs were present in normal amounts in fibroblast extracts from several subtypes and variants of Gaucher disease. The largest poly (A)+ mRNA species was thought to represent an unspliced nuclear precursor for the two smaller beta-Glc mRNAs. S1 nuclease analyses, using SP6 transcripts of beta-Glc cDNA, indicated that the 2,000 nucleotide mRNA differs from the 2,500 nucleotide form at both the 5' and 3' ends. These results are consistent with the use of an alternate 5' splice site and 3' polyadenylation signal. These results also suggest that the subtype and variants of Gaucher disease result from single base alterations that lead to the synthesis of defective beta-Glc.

Fabry disease: twenty-three mutations including sense and antisense CpG alterations and identification of a deletional hot-spot in the alpha-galactosidase A gene.

Fabry disease, an X-linked inborn error of glycosphingolipid catabolism, results from mutations in the alpha-galactosidase A gene at Xq22.1. To determine the nature and frequency of the molecular lesions causing the classical and milder variant Fabry phenotypes, and for precise carrier detection in Fabry families, the alpha-galactosidase A coding and flanking intronic sequences from 23 unrelated Fabry hemizygotes were analyzed. In patients with the classic phenotype, 16 new missense and nonsense mutations and four small exonic gene rearrangements were identified: C52S, C56F, E59K, L89R, R100K, R112H, L131P, A143P, G144V, C172Y, D244N, N272K, A288D, W81X, Q99X, Q157X, R301X, 25del1, 333del18, 358del6, and 1020del1. The R112H mutation at a CpG dinucleotide resulted in residual activity and a mild variant phenotype while the R112C lesion caused the classic disease manifestations, defining a genotype/phenotype correlation for sense and antisense mutations at the same CpG dinucleotide. In addition, two complex rearrangements, each involving two mutational events, occurred in classic hemizygotes. Both rearrangements resulted in missense mutations that did not change the reading frame. Notably, three of the deletions occurred within 11 codons in exon 2, thereby defining a 'hot-spot' for deletions. These studies revealed that most mutations in the alpha-galactosidase A gene causing Fabry disease were private, that codons 111-122 defined a deletion hot-spot, and that different substitutions of the same codon resulted in markedly different disease phenotypes.

Hexosaminidase A activity and amyotrophic lateral sclerosis.

Abnormalities of GM2 ganglioside metabolism owing to hexosaminidase A (Hex A) deficiency have been associated with ALS phenotypes. The clinical features described in these ALS patients with Hex A deficiency include early onset, positive family history, and/or long disease duration. In an attempt to determine prospectively the incidence of Hex A deficiency within an ALS population, the records of The Mount Sinai Medical Center ALS Clinic were reviewed to select those patients with "atypical" ALS (total N = 52), i.e. onset before age 35, positive family history, and/or disease duration greater than 90 months. The control group (total N = 50), "typical" ALS patients, did not fulfill any of these historical criteria. Hex A activity determined in isolated peripheral blood leukocytes was normal in all typical ALS patients (mean 67.3%). Hex A deficiency was not found in any atypical ALS patients. Thus, Hex A deficiency apparently is an unusual etiology of typical or atypical ALS but is of medical and genetic importance in individual families.

Metachromatic leucodystrophy in three families from Nova Scotia, Canada: a recurring mutation in the arylsulphatase A gene.

Metachromatic leucodystrophy (MLD) is a lysosomal storage disease resulting from a deficiency of arylsulphatase A. We have identified a child with infantile onset MLD who is homozygous for an A212V mutation, a mutation previously reported but not further characterised. We have introduced this mutation into an arylsulphatase A expression vector by site directed mutagenesis. Transient expression of this mutant plasmid in COS cells yields very low levels of arylsulphatase A activity consistent with the patient's phenotype. The arylsulphatase A pseudodeficiency also segregates in this family causing difficulty in interpreting enzyme levels in the absence of DNA data. Two other patients from the same province, also carrying the A212V allele, have juvenile and adult onset MLD and are heterozygous for P426L ("A" allele) and I179S alleles respectively, known late onset alleles.

Manifestations and treatment of Schimke immuno-osseous dysplasia: 14 new cases and a review of the literature.

UNLABELLED: Schimke immuno-osseous dysplasia (SIOD) is a rare autosomal recessive spondylo-epiphyseal dysplasia. The characteristic features of SIOD include 1) short stature with hyperpigmented macules and an unusual facies, 2) proteinuria with progressive renal failure, 3) lymphopenia with recurrent infections, and 4) cerebral ischaemia. Although 25 patients have been reported with this disorder, the clinical course and phenotype of SIOD are not well characterized. This report summarizes the clinical findings, course and treatment of reported patients and includes 14 additional patients with SIOD. We emphasize the high incidence of cerebral ischaemia and ocular abnormalities, define the high incidence of thyroid dysfunction and blood cytopenia, and confirm the absence of effective and durable medical therapies. CONCLUSION: Schimke immuno-osseous dysplasia is a multi-system autosomal recessive disorder with variable expression that affects the skeletal, renal, immune, vascular, and haematopoietic systems. Medical therapy is limited especially for more severely affected individuals.