Phenotypic variability at the TGF-beta1 locus in Camurati-Engelmann disease

Camurati-Engelmann disease (CED) [OMIM 131300] is an autosomal dominant sclerosing bone dysplasia recently ascribed to mutations of the transforming growth factor (TGF-beta1) gene on chromosome 19q13.1-q13.3. Five mutations consistently located in the TGF-beta1 propeptide have been hitherto identified in 21 families. Here, we report on TGF-beta1 mutations in one Australian and six European families. Three distinct mutations were identified among seven families: namely, R218H (family 1), R218C (families 2, 6, 7) and C225R (families 3, 4, 5). The three mutations identified in our pedigrees have been previously observed in families of Japanese and Israeli origin and the R218C appears to be the most prevalent mutation worldwide (17/28 reported families). No obvious correlation between the nature of the mutations and the severity of the clinical manifestations could be established, but a marked intrafamilial clinical variability was observed, supporting incomplete penetrance of CED. Interestingly, the polymorphisms in the TGF-beta1 gene showed no correlation with the severity of the disease. We conclude that CED is a clinically variable condition and that this clinical variability is not accounted for by polymorphisms at the TGF-beta1 locus.

Acromicric dysplasia: long term outcome and evidence of autosomal dominant inheritance

Acromicric dysplasia is a rare bone dysplasia characterised by short stature, short hands and feet, normal intelligence, mild facial dysmorphism, and characteristic x ray abnormalities of the hands. Only a very small number of children with this condition have been reported so far. Here we report on a series of 22 patients including 10 boys and 12 girls with acromicric dysplasia. Length was normal at birth and height fell progressively off the centiles postnatally. The mean adult height was 130 cm (133 cm in males, 129 cm in females). The hands, feet, and limbs were short and OFC was normal. Intelligence was normal and mild dysmorphic features were noted. Other occasional features included well developed muscles, a hoarse voice, generalised joint limitation in some patients, frequent ear, tracheal, and respiratory complication, and spine abnormalities. Long term follow up showed that facial dysmorphism was less obvious in adults and that carpal tunnel syndrome was frequent in older patients. Apart from short metacarpals and phalanges, internal notch of the second metacarpal, external notch of the fifth metacarpal, and internal notch of the femoral heads, there were no major x ray abnormalities. No major complications, such as cardiac disease or major orthopaedic problems, occurred in the course of the disease. The condition appeared to be sporadic in 16 cases but the observation of vertical transmission in three families was consistent with an autosomal dominant mode of inheritance.

Absent lacrimal ducts, distichiasis, dysmorphic features, and brachydactyly: a case report

We report a male patient presenting with the association of absent lacrimal ducts, distichiasis, dysmorphic facial features and limb abnormalities. Extensive chromosomal studies showed normal chromosomes. We discuss differential diagnoses such as Setleis, Char and Lacrimo-Auriculo-Dento-Digital (LADD) syndromes. This may represent a novel entity for which parental consanguinity would support an autosomal recessive mode of inheritance.

Pierre Robin sequence: a series of 117 consecutive cases

A series of 117 cases of Pierre Robin Sequence are classified as isolated (48%), syndromic (35%), and with associated anomalies (17%); the latter group had a poor long-term prognosis. In isolated Pierre Robin Sequence, familial cases and a high incidence of twins were noted. Among syndromic Pierre Robin Sequence, 4 syndromes represent more than 50% of the diagnoses.

Severe mental retardation, short stature, facial anomalies, joint laxity, and dislocations in two sisters: previously undescribed MCA/MR syndrome

We describe two sisters with short stature, obesity, "bulbous" nasal tip, microretrognathism, brachydactyly, joint hyperlaxity and dislocation, and mental retardation. Skeletal surveys disclosed widened mandibular angles, thin temporal processes, hypoplastic clavicles, short distal ends of ulnae, short fourth metacarpals, and dislocation of hips, elbows, and thumbs. The parents are first cousins. To the best of our knowledge, this combination of multiple congenital anomalies and mental retardation has not been reported before.

A novel syndrome with dwarfism, poorly muscled build, absent clavicles, humeroradial fusion, slender bones, oligodactyly and micrognathia

We report on a 15-year-old girl with severe pre- and post-natal growth retardation, poorly muscled build, micrognathia, ulnar ray oligodactyly, absent clavicles, abnormal scapulae, humeroradial fusion, hip dislocation, small iliac wings, slender tubular bones and normal intelligence. An extensive search has failed to ascribe this association to a known condition. This child shared some clinical and radiological features with the Yunis-Varon syndrome but the normal intelligence and the ulnar ray oligodactyly of our patient does not support this diagnosis.

Neurological presentation of a congenital disorder of glycosylation CDG-Ia: implications for diagnosis and genetic counseling

The congenital disorders of glycosylation (CDG) constitute a new group of recessively inherited metabolic disorders that are characterized biochemically by defective glycosylation of proteins. Several types have been identified. CDG-Ia, the most frequent type, is a multisystemic disorder affecting the nervous system and numerous organs including liver, kidney, heart, adipose tissue, bone, and genitalia. A phosphomannomutase (PMM) deficiency has been identified in CDG-Ia patients and numerous mutations in the PMM2 gene have been identified in patients with a PMM deficiency. We report on a French family with 3 affected sibs, with an unusual presentation of CDG-Ia, remarkable for 1) the neurological presentation of the disease, and 2) the dissociation between intermediate PMM activity in fibroblasts and a decreased PMM activity in leukocytes. This report shows that the diagnosis of CDG-Ia must be considered in patients with non-regressive early-onset encephalopathy with cerebellar atrophy, and that intermediate values of PMM activity in fibroblasts do not exclude the diagnosis of CDG-Ia.

Partial maternal heterodisomy of chromosome 17q25 in a case of severe mental retardation

We report a segmental maternal uniparental heterodisomy of chromosome 17 (mat UPD17) in a 3-year-old boy presenting with hyperactivity, major instability, mental retardation and facial dysmorphism. Since conventional and high resolution karyotypes were normal, this patient was tested for cryptic telomeric rearrangements by using the recently developed fluorescent genotyping-based technology. The mat UPD17 segment extended for a small 11-cM region of the distal chromosome 17q. Trisomy 17 in circulating lymphocytes and skin fibroblasts was excluded. Our finding emphasizes the potential use of fluorescent genotyping to detect uniparental disomies and suggests that chromosome 17q25 should contain one or several imprinted genes of particular importance for brain development.

Respiratory chain deficiency in Alpers syndrome

Alpers syndrome is a progressive encephalopathy of early onset, characterized by rapid and severe developmental delay, intractable seizures and liver involvement in a previously healthy child. Here, we report on respiratory chain enzyme deficiency in the liver of four unrelated children presenting with epileptic encephalopathy and liver involvement diagnosed as Alpers syndrome. Interestingly, oxidative phosphorylation in skeletal muscle was normal in 4/4 and blood and CSF lactate in 3/4 patients. Liver involvement had a late clinical onset in patients with previously isolated epileptic encephalopathy. Based on these observations, we suggest 1. to give consideration to respiratory chain deficiency in the diagnosis of severe epileptic encephalopathy in childhood, even when no clinical or biological evidence of liver involvement or lactic acidosis is noted, and 2. to investigate the respiratory chain in a needle biopsy of the liver in children with epileptic encephalopathy prior to valproate administration if biochemical indications for respiratory chain disease or hepatic disturbance are noted, as this drug is believed to occasionally trigger hepatic failure and fatal outcome.

A novel automated strategy for screening cryptic telomeric rearrangements in children with idiopathic mental retardation

Cryptic unbalanced subtelomeric rearrangements are known to cause a significant proportion of idiopathic mental retardation in childhood. Because of the limited sensitivity of routine analyses, the cytogenetic detection of such rearrangements requires molecular techniques, namely FISH and comparative genomic hybridisation (CGH). An alternative approach consists in using genetic markers to detect segmental aneusomy. Here, we describe a new strategy based upon automated fluorescent genotyping to search for non mendelian segregation of telomeric microsatellites. A total of 29 individuals belonging to 24 unrelated families were screened and three abnormal patterns of segregation were detected (two rearrangements and one parental disomy). This study gives strong support to the view that cryptic telomeric rearrangements significantly contribute to idiopathic mental retardation and demonstrates that fluorescent genotyping is a very sensitive and cost-effective method to detect deletions, duplications and uniparental disomies.

"Baby rattle" pelvis dysplasia

We report an apparently previously undescribed lethal skeletal dysplasia, clinically resembling achondrogenesis, but with distinct radiologic and chondro-osseous morphologic features. These comprise bifid distal ends of the long bones of the limbs, absent vertebral body ossification, a unique "baby rattle" pelvic configuration with tall and broad ilia, absent endochondral ossification, regions of mesenchymal cells within the resting cartilage, and abnormal mesenchymal ossification.

Orthotopic liver transplantation for mitochondrial respiratory chain disorders: a study of 5 children

BACKGROUND

Liver involvement in mitochondrial respiratory chain disorders (MRCD) frequently ends in liver failure and death. Because of the high risk of extrahepatic, particularly neuromuscular, manifestations of the disease, the indication of orthotopic liver transplantation (OLT) in these patients remains controversial. We report on 5 such children in whom OLT was carried out, in an attempt to help clarify the matter.

PATIENTS

Patients 1 and 2 presented with fulminant liver failure at ages 7 and 6 months respectively. Emergency liver transplantation was performed before etiological investigations were completed. Retrospective examination of the explanted livers showed defects in complexes I, III and IV. In patient 1, severe neurological deterioration occurred 2 months after OLT with fatal outcome 9 months later. Patient 2 is alive 22 months after OLT with moderate motor impairment. Patients 3, 4 and 5 presented with progressive liver failure before 6 months of age. Surgical liver biopsies displayed a 50% defect in complex IV (patient 3), a defect in complexes I, IV (patient 4) and in complexes I, III, IV (patient 5). Because there was no clinical extrahepatic involvement on investigations, OLT was carried out in these patients. Patient 3 died of multiple organ failure soon after OLT, patients 4 and 5 are alive respectively 21 months and 12 months after OLT with normal neurological examination.

CONCLUSION

OLT may be a valid therapeutic option in infants with delayed liver cell failure due to MRCD, only after performing in emergency a thorough inves tigation to exclude clinically significant extrahepatic, especially neuromuscular, involvement.

Mazabraud syndrome in two patients: clinical overlap with McCune-Albright syndrome

Mazabraud syndrome is a rare sporadic disorder, mainly characterized by bone fibrous dysplasia and intramuscular myxomas. We report here two new cases of Mazabraud syndrome. One of our patients (Patient 1) also had café-au-lait spots and multinodular goiter suggestive of McCune-Albright syndrome. We review the 37 previously reported cases with Mazabraud syndrome and discuss the 6/37 patients with criteria of Mazabraud and McCune-Albright syndromes. Based on the clinical overlap between the two syndromes, we tested the GNAS1 gene in blood leukocytes and skin fibroblasts of Patient 1, but found no evidence of an activating mutation in the GNAS1 gene.

MECP2 mutation in non-fatal, non-progressive encephalopathy in a male

To study the clinical overlap between Rett (RTT) and Angelman syndromes (AS), we screened the MECP2 gene in a cohort of 78 patients diagnosed as possible AS but who showed a normal methylation pattern at the UBE3A locus. MECP2 missense (R106W, G428S), nonsense (R255X, R270X), and frameshift mutations (803 delG) were identified in 6/78 patients including 4/6 female cases consistent with RTT, one female case with progressive encephalopathy of neonatal onset, and one isolated male case with non-fatal, non-progressive encephalopathy of neonatal onset. This study shows that MECP2 mutations can account for a broad spectrum of clinical presentations and raises the difficult issue of the screening of the MECP2 gene in severe encephalopathy in both males and females.

Temporal bone anomaly proposed as a major criteria for diagnosis of CHARGE syndrome

The acronym CHARGE defines a non-random clustering of congenital malformations of unknown origin. Classical diagnostic criteria include: 1) one major feature namely coloboma/microphthalmia or choanal atresia, and 2) four of the six features designated in the CHARGE acronym. Interestingly, all CHARGE patients hitherto reported had partial or complete semicircular canal hypoplasia on temporal bone CT-scan. We report on semicircular canal agenesis/hypoplasia in three patients with three to four features of the CHARGE syndrome and neither coloboma nor choanal atresia and we propose to include temporal bone malformations as a major criteria for diagnosis of CHARGE syndrome.

"Duplicate calcaneus": a rare developmental defect observed in several skeletal dysplasias

Duplication of the calcaneus is a rarely observed radiographic finding that probably results from delayed coalescence of two primary calcaneal centers of ossification. We performed a review of 2,500 computerized cases of skeletal dysplasias and syndromes with bone involvement in the International Skeletal Dysplasia Registry, searching for those cases in which a duplicate calcaneus had been recorded. We found that it was a non-random feature of three skeletal dysplasias and groups comprising thanatophoric dysplasia and the chondrodysplasia punctata and short rib (polydactyly) groups. We conclude that duplication of the calcaneus should be considered a consistent feature of these entities and may reflect a more generalized developmental defect.

A broad spectrum of clinical presentations in congenital disorders of glycosylation I: a series of 26 cases

INTRODUCTION

Congenital disorders of glycosylation (CDG), or carbohydrate deficient glycoprotein syndromes, form a new group of multisystem disorders characterised by defective glycoprotein biosynthesis, ascribed to various biochemical mechanisms.

METHODS

We report the clinical, biological, and molecular analysis of 26 CDG I patients, including 20 CDG Ia, two CDG Ib, one CDG Ic, and three CDG Ix, detected by western blotting and isoelectric focusing of serum transferrin.

RESULTS

Based on the clinical features, CDG Ia could be split into two subtypes: a neurological form with psychomotor retardation, strabismus, cerebellar hypoplasia, and retinitis pigmentosa (n=11), and a multivisceral form with neurological and extraneurological manifestations including liver, cardiac, renal, or gastrointestinal involvement (n=9). Interestingly, dysmorphic features, inverted nipples, cerebellar hypoplasia, and abnormal subcutaneous fat distribution were not consistently observed in CDG Ia. By contrast, the two CDG Ib patients had severe liver disease, enteropathy, and hyperinsulinaemic hypoglycaemia but no neurological involvement. Finally, the CDG Ic patient and one of the CDG Ix patients had psychomotor retardation and seizures. The other CDG Ix patients had severe proximal tubulopathy, bilateral cataract, and white matter abnormalities (one patient), or multiorgan failure and multiple birth defects (one patient).

CONCLUSIONS

Owing to the remarkable clinical variability of CDG, this novel disease probably remains largely underdiagnosed. The successful treatment of CDG Ib patients with oral mannose emphasises the paramount importance of early diagnosis of PMI deficiency.

Hypertelorism-Microtia-Clefting syndrome (Bixler syndrome): report of two unrelated cases

The association of Hypertelorism, Microtia and Cleft lip and palate (HMC syndrome, MIM 239800) is a rare condition of autosomal recessive inheritance. A total of seven cases of HMC syndrome in five families have been hitherto reported. Here, we report two unrelated cases and put emphasis on the possible normal psychomotor development in this syndrome.