The cerebro-reno-digital syndromes: a new community

Sibs with acrocephalopolydactylous dysplasia (Elejalde syndrome) in a non-consanguineous family

Acrocephalopolydactylous dysplasia, (Elejalde syndrome) is a rare condition; only six cases have been reported to date. We describe two infants born with Elejalde syndrome (ES); compare the clinical, pathological, and histological findings with those of known cases of Elejalde syndrome. The post-mortem histology study of the skin shows hyperplasia of connective tissues, a diagnostic sign in this condition. We describe cardiomegaly, cleft palate, and cryptorchidism not reported previously.

Acral and renal malformations following ICSI

This case reports a delivery of a child with limb and renal malformations following intracytoplasmic sperm injection. A 29-year-old woman and a 39-year-old man with primary infertility underwent IVF-ICSI-ET therapy cycle. The couple delivered an infant with acrorenal syndrome. When assisted reproductive techniques are used, especially ICSI, the risk of genetics abnormalities should be discussed in detail with the couple and sufficient informed consent should be obtained before starting IVF-ET procedures.

Elejalde syndrome—A case report

Elejalde syndrome (McKusick 200995), also known as acrocephalopolydactylous dysplasia, is a rare condition. We describe a sixth patient with this syndrome which is characterized by craniosynostosis and hyperproliferation of fibroblasts in many tissues including skin, liver, kidney, and pancreas. The cause of the syndrome is the homozygous state of an autosomal recessive mutation. We present a hypothesis that Elejalde syndrome might be associated with an inactivating FGFR gene mutation.

Renal defects and limb deficiencies in 197 infants: is it possible to define the "acrorenal syndrome"?

Dieker and Opitz in 1969 described the simultaneous occurrence of limb deficiencies (LDs) and renal anomalies (RAs) in three patients. Curran and Curran introduced in 1972 the term "acrorenal syndrome." Since then, the term "acrorenal syndrome" is used occasionally, but a well-circumscribed definition has never been established. On the other hand, the concept of an acrorenal polytopic developmental field defect was postulated by Opitz and others to explain the association between RAs and LDs. We undertook this study to investigate whether this acrorenal "syndrome" could be identified in a large group of cases with congenital RAs and a limb deficiency. Eleven birth defect registries that are part of the International Clearinghouse for Birth Defects Monitoring (i.e., registries of ICBDMS in Finland, France [Paris and Strasbourg], Israel, Italy [IPIMC and Emilia Romagna], Mexico, Northern Netherlands, South America, Spain, and the United States [Atlanta]) provided data on 815 infants who had a LD and at least one other major congenital anomaly. These 815 cases were ascertained among 5,163,958 births. We selected the 197 cases who had both a limb deficiency and a renal or urinary tract anomaly. In about 50% of these cases a diagnosis or a recognized phenotype was reported, with chromosomal aberrations and VACTERL being most frequent. In the group with no diagnosis or recognized phenotype (95 cases), we looked for (a) clustering of specific types of LDs and RAs, and (b) for clustering of associated anomalies, in order to find evidence for and be able to define better the term "acrorenal syndrome." Our data suggest that an association exists between LDs and RAs, possibly explained by the concept of the acrorenal polytopic developmental field defect. However, our dataset does not yield evidence for the existence of one distinct "syndrome," defined as a pattern of causally related multiple anomalies. Therefore, use of the term "acrorenal syndrome" should be avoided.

Antenatal presentation of Bardet-Biedl syndrome may mimic Meckel syndrome

Bardet-Biedl syndrome (BBS) is a multisystemic disorder characterized by postaxial polydactyly, progressive retinal dystrophy, obesity, hypogonadism, renal dysfunction, and learning difficulty. Other manifestations include diabetes mellitus, heart disease, hepatic fibrosis, and neurological features. The condition is genetically heterogeneous, and eight genes (BBS1-BBS8) have been identified to date. A mutation of the BBS1 gene on chromosome 11q13 is observed in 30%-40% of BBS cases. In addition, a complex triallelic inheritance has been established in this disorder--that is, in some families, three mutations at two BBS loci are necessary for the disease to be expressed. The clinical features of BBS that can be observed at birth are polydactyly, kidney anomaly, hepatic fibrosis, and genital and heart malformations. Interestingly, polydactyly, cystic kidneys, and liver anomalies (hepatic fibrosis with bile-duct proliferation) are also observed in Meckel syndrome, along with occipital encephalocele. Therefore, we decided to sequence the eight BBS genes in a series of 13 antenatal cases presenting with cystic kidneys and polydactyly and/or hepatic fibrosis but no encephalocele. These fetuses were mostly diagnosed as having Meckel or "Meckel-like" syndrome. In six cases, we identified a recessive mutation in a BBS gene (three in BBS2, two in BBS4, and one in BBS6). We found a heterozygous BBS6 mutation in three additional cases. No BBS1, BBS3, BBS5, BBS7, or BBS8 mutations were identified in our series. These results suggest that the antenatal presentation of BBS may mimic Meckel syndrome.

Development of multiorgan pathology in thewpk rat model of polycystic kidney disease

Rodent models of polycystic kidney disease (PKD) have provided valuable insight into the cellular changes associated with cystogenesis in humans. The present study characterizes the morphology of renal and extrarenal pathology of autosomal recessive PKD induced by the wpk gene in Wistar rats. In wpk(-/-) rats, proximal tubule and collecting duct cysts develop in utero and eventually consume the kidney. Increased apoptosis, mitosis, and extracellular tenascin deposition parallel cyst development. Extrarenal pathology occurs in the immune system (thymic and splenic hypoplasia) and central nervous system (CNS; hypoplasia to agenesis of the corpus callosum with severe hydrocephalus). Severity of hydrocephalus varied inversely with size of the corpus callosum. In wpk(-/-) rats, the corpus callosum exhibits relatively few axons that cross the midline. This CNS pathology is similar to that described in three human renal cystic syndromes: orofaciodigital, genitopatellar, and cerebrorenal-digital syndromes. Collecting duct and ventricular ependymal cilia appear morphologically normal. To determine if rodent background strain and the presence of modifier genes affect severity of the disease, we crossed the Wistar-wpk rat with Brown Norway (BN) and Long Evan (LE) rats and found the degree of renal and cerebral pathology was diminished as evidenced by lower kidney weight as a percent of body weight and serum urea nitrogen concentration in cystic rats on LE or BN strains as well as less prominent cranial enlargement. Crosses with BN rats allowed us to localize the wpk gene on chromosome 5 very close to the D5Rat73 marker. The wpk gene lies within a chromosomal region known to harbor a PKD modifier locus. In summary, the types of renal and cerebral pathology seen in the Wistar wpk rat are a unique combination seen only in this rodent model.

Malformations of cranial base structures and pituitary gland in prenatal Meckel syndrome

The sella turcica region, including the clivus and the pituitary gland, was studied histologically in five human fetuses with Meckel syndrome (MS). All cases had malformed sella turcica and malformed clivus with irregularly shaped notochordal remnants. We consider that these three characteristics are constant phenotypic traits in MS. The adenohypophysis was present in three cases. In one of these, ectopia of the gland occurred with adenopituitary tissue overlying the dorsum sella, and in another remnants were found in the pharyngeal submucosa. In two fetuses the neurohypophysis was not found. The findings in the region were compared to normal findings and to findings in trisomy 18, where cranial base structures radiographically appeared similar to those in MS. We conclude that in MS specific characteristics are found in the cranial base region and that radiographic analysis needs to be supplemented by histological analysis when studying this specific region.

A gene for Meckel syndrome maps to chromosome 11q13

Meckel syndrome (MKS) is a rare autosomal recessive lethal condition of unknown origin, characterized by (i) an occipital meningo-encephalocele with (ii) enlarged kidneys, with multicystic dysplasia and fibrotic changes in the portal area of the liver and with ductal proliferation, and (iii) postaxial polydactyly. A gene responsible for MKS in Finland has been mapped to chromosome 17q21-q24. Studying a subset of Middle Eastern and northern African MKS families, we have recently excluded the chromosome 17 region and have suggested a genetic heterogeneity. In the present study, we report on the mapping of a second MKS locus (MKS2) to chromosome 11q13, by homozygosity mapping in seven families that do not show linkage to chromosome 17q21-q24 (maximum LOD score 4.41 at recombination fraction .01). Most interestingly, the affected fetuses of southern Tunisian ancestry shared a particular haplotype at loci D11S911 and D11S906, suggesting that a founder effect is involved. Our observation gives support to the clinical and genetic heterogeneity of MKS.

Meckel syndrome

Meckel syndrome (MKS) is a lethal syndrome with a central nervous system malformation, usually occipital meningoencephalocele, bilaterally large multicystic kidneys with fibrotic changes of the liver, and polydactyly in most cases. Additional anomalies are frequent. A common characteristic of the parenchymal changes of many organs is a proliferation of the stromal connective tissue and increase and dilatation of the associated epithelial ducts. Autosomal recessive inheritance is well confirmed and the gene locus has been mapped to chromosome 17q21-24 by genome wide linkage study. The locus was later refined to within a less than 1 cM region (17q22), in which most of the Finnish MKS patients share a common chromosomal haplotype suggesting one major and relatively old mutation. However, in most of the non-Finnish MKS families studied, this linkage could not be confirmed. The linkage studies provide evidence that more than one locus is involved in bringing about the combination of CNS malformations, cystic kidneys, and polydactyly, maybe even in typical cases of MKS. Prenatal diagnosis of MKS by vaginal ultrasound scan is possible from 11-12 weeks of pregnancy, especially in families where there is a known risk. In those families where linkage to 17q22 is established, prenatal diagnosis by DNA analysis is possible.

Genetic heterogeneity of Meckel syndrome

Meckel syndrome (MKS) is a lethal, autosomal recessive condition characterised by an occipital meningoencephalocele, enlarged kidneys with multicystic dysplasia, fibrotic changes of the liver in the portal area with ductal proliferation, and postaxial polydactyly. Recently, a MKS gene has been mapped to chromosome 17q21-q24 in Finnish families, with no evidence of locus heterogeneity in this population. Here, we report the exclusion of chromosome 17q21-q24 in eight typical MKS families of North African and Middle Eastern ancestry and provide evidence for genetic heterogeneity of this condition.

Elejalde syndrome: a case report

Elejalde syndrome is a rare condition comprising a high birth weight, swollen globular body, a short neck with redundant skin folds, postaxial polydactyly, omphalocele, enlarged liver and kidneys, and renal dysplasia. The syndrome, also known as acrocephalopolydactylous dysplasia, is thought to be an autosomal recessive trait. We report on a liveborn infant with this condition.

Dandy-Walker malformation in the Meckel syndrome

The Meckel syndrome (MS) is an autosomal recessive disorder classically defined by the triad of occipital encephalocele, multicystic kidneys, and polydactyly. Here we describe 3 sibs with varying manifestations of MS. The propositus had isolated cystic renal disease. The other sibs were both prenatally diagnosed with renal disease, polydactyly, and the Dandy-Walker malformation, an unusual central nervous system defect in MS. These findings are discussed in the context of the phenotypic expression of MS and the nosology of this disorder and the cerebro-reno-digital (Meckel-like) syndromes.

Cerebro-reno-digital syndrome in two sibs

We describe two sibs with mental retardation, facial anomalies, polydactyly, cerebellar vermis agenesis, and either meningocele or renal cystic dysplasia. The patients' condition appears to belong to a group of cerebro-reno-digital syndromes. Autosomal recessive inheritance is suggested.

Cerebro-reno-digital (Meckel-like) syndrome with Dandy-Walker malformation, cystic kidneys, hepatic fibrosis, and polydactyly

We report on a boy with several findings of the Meckel syndrome, such as hepatic fibrosis, polycystic kidneys, post-axial hexadactyly, and genital abnormalities, but a Dandy-Walker malformation rather an occipital meningocele. Progressive deterioration of renal function beginning at 37 months led to death at 43 months. Both Dandy-Walker malformation and survival to the fourth year are unusual findings in Meckel syndrome. This uncommon combination represents a further demonstration of the pleiotropy/heterogeneity of the cerebro-reno-digital syndromes.

Patterns of acrorenal malformation associations

Limb and urinary tract defects have frequently been reported to occur together as components of a single acrorenal field defect or in many multiple malformation syndromes. However, the concordance of such anomalies has rarely been studied on a population basis or the relationships between specific limb and renal defects defined. This paper documents the patterns of acrorenal associations seen in over 1,500,000 infants born in Hungary in 1975-1984. In all, 1 in 1,800 infants had a limb deficiency and 9% of these (75 cases) had a urinary tract anomaly. Urinary tract anomalies were most commonly seen with radial ray defects, micromelia and amelia. The commonest recognized patterns were VACTERL association and the cloacal exstrophy and caudal regression sequences. Chromosomal and single gene defects also occurred. Numerical taxonomic techniques delineated six main clusters of patients. Important groupings included micromelia with renal agenesis, split hand/foot with hydronephrosis, and radial ray anomalies with VACTERL defects. The radial ray groups differed in the nature of the VACTERL anomalies seen and with respect to laterality, symmetry, and non-VACTERL anomalies. There was a strong association of bilateral limb defects with bilateral renal anomalies and unilateral with unilateral. Ipsilateral defects tended to occur in typical VACTERL cases, while contralateral defects tended to occur with additional non VACTERL midline anomalies. Although renal and limb anomalies are associated, in almost all cases malformations in other systems are also present. The precise nature of the malformation patterns seen appear to reflect differences in the nature and magnitude of the underlying dysmorphogenetic processes as well as the timing of their effects.

Digito-reno-cerebral syndrome: confirmation of Eronen syndrome

In 1985, Eronen et al. described a new autosomal recessive syndrome with absence of the distal phalanges of the toes and fingers, renal defect and cerebral anomalies (dilated ventricles or seizures). Two unrelated children affected by this syndrome enable us to accept its autonomy and delineate its nosology. Variability of the expression of the renal and cerebral manifestations is emphasized.