Tapetoretinal degeneration in brothers with apparent Cohen syndrome: nosology with Mirhosseini-Holmes-Walton syndrome.

We report on 2 brothers with marked eye anomalies, documented with histopathological studies, and several other findings fitting the diagnosis of both the Cohen and the Mirhosseini-Holmes-Walton syndromes. In accordance with Norio and Raitta (Norio R, Raitta C (1986): Am J Med Genet 25:397-398) we come to the conclusion that these 2 syndromes constitute one clinical but possibly heterogeneous entity.

Mental retardation, acromegalic face, and megalotestes in two half-brothers: a specific form of X-linked mental retardation without fra(X) (q)?

We describe a family with two half-brothers affected with severe mental retardation. The phenotype in the affected individuals is characterized by apparent acromegaly, profound mental retardation, and hyperactivity. The mother has analogous but less severe facial anomalies and mild mental impairment. Screening for fra(X) (q) was negative in peripheral lymphocytes using methotrexate for fra(X) enhancement. The clinical findings in our patients are similar to those described by Fryns et al. [1986] in two patients with acquired lesions of the central nervous system. CT investigations in one of our patients showed areas of hyperdensity in the pontine region and a small subarachnoid cyst. The pedigree suggests X-linked inheritance. The association of apparent acromegaly, CNS anomalies, megalotestes, and mental retardation in this family supports the hypothesis that a distinct syndrome may exist with phenotype anomalies more severe than those characteristic for the Martin-Bell syndrome but without fragile X.

Misclassification risk of patients with bilateral cleft lip and palate and manifestations of median facial dysplasia: A new variant of del(22q11.2) syndrome?

The generic term median facial dysplasia (MFD) describes a subgroup of patients with cleft lip and palate exhibiting characteristic craniofacial defects: (1) short prolabium, (2) absence of frenulum labii, (3) hypoplasia of premaxilla, (4) absent upper central and lateral incisors of the cleft side, and (5) deficient septal cartilage and nasal spine. Gross brain malformations are usually absent in MFD. The same craniofacial malformations are also described in patients with holoprosencephaly sequence (HPE-S). We report on two male patients with bilateral cleft lip and palate showing the facial findings of MFD or HPE-S. Additional congenital malformations were anal atresia in one patient and severe cardiac defect in the other. In both, HPE was excluded by brain imaging, although uncommon brain anomalies were detected consisting of multiple white-matter lesions in the one patient and unusual enlargement and tortuosity of intracerebral blood vessels in both patients. In addition to facial anomalies, the patients also had psychiatric problems typically seen in velo-cardio-facial syndrome (VCFS). Fluorescence in situ hybridization (FISH) analysis confirmed a 22q11.2 microdeletion in both.

Two sisters with Escobar syndrome.

We report on 2 sisters with an autosomal-recessive multiple pterygium syndrome, type Escobar, consisting of multiple pterygia with severe contractures, short stature, and minor facial and external genital anomalies. The striking finding was severe muscular atrophy. We speculate that a neuromuscular disorder is the underlying pathogenesis of Escobar syndrome.

Bilateral radial deficiency with lower limb involvement.

We describe a 10-month-old boy with an unclassified form of radial aplasia with absent thumbs, tibia hypo/-aplasia, and partial absence of toes. Only a few cases with similar limb deficiencies have been published. We try to classify the malformations on the basis of embryological considerations and discuss possible differential diagnosis.

Rare dental abnormalities seen in oculo-facio-cardio-dental (OFCD) syndrome: three new cases and review of nine patients.

Oculo-facio-cardio-dental syndrome is a very rare condition. So far, only nine cases have been documented. We report on three additional female patients representing the same entity. The clinical findings were: congenital cataract, microphthalmia/microcornea, secondary glaucoma, vision impairment, ptosis, long narrow face, high nasal bridge, broad nasal tip with separated cartilages, long philtrum, cleft palate, atrial septal defect, ventricular septal defect, and skeletal anomalies. The following dental abnormalities were found: radiculomegaly, delayed dentition, oligodontia, root dilacerations (extension), and malocclusion. For the first time, fusion of teeth and hyperdontia of permanent upper teeth were seen. In addition, structural and morphological dental changes were noted. These findings expand the clinical spectrum of the syndrome.

A case of Perlman syndrome: fetal gigantism, renal dysplasia, and severe neurological deficits.

We report on a neonate presenting with polyhydramnios; macrosomia; macrocephaly; visceromegaly including bilateral nephromegaly, hepatomegaly, cardiomegaly; thymus hyperplasia; cryptorchidism; generalized muscle hypotonia; and a distinctive facial appearance. The clinical course was marked by severe neurodevelopmental deficits combined with progressive respiratory decompensation leading to death at the age 6 months. Magnetic resonance imaging (MRI) disclosed a generalized cerebral atrophy with a marked deficit of the white matter. Renal ultrasound and MRI showed markedly enlarged kidneys with multiple small cystic lesions, a pattern indistinguishable from polycystic kidney disease. The postmortem kidney biopsy revealed dysplastic changes, microcysts, and a focal nephrogenic rest, characteristic features of the Perlman syndrome. In children with fetal gigantism, renal abnormalities, and neurological deficits, Perlman syndrome should be considered and may be confirmed by kidney biopsy.

Short-rib-polydactyly syndrome type Verma-Naumoff-Le Marec in a fetus with histological hallmarks of type Saldino-Noonan but lacking internal organ abnormalities.

Up to seven short-rib-polydactyly (SRP) syndromes have been identified so far with marked clinical and pathological overlap. We describe a 32-week-old, nonhydropic male fetus with thoracic "dysplasia," short limbs, and unilateral postaxial polydactyly. All internal organs were normally developed, including the central nervous system. The external genitalia were unambiguously male, in accordance with a 46,XY karyotype. Radiological signs most closely resembled those of SRP, type Le Marec, though histology of the femoral physeal growth zone was consistent with the Saldino-Noonan type. The remarkable lack of visceral anomalies in conjunction with the radiological and histological findings further adds to the phenotypic spectrum of the SRP syndromes. The histological analysis in this case supports a close relationship between types Saldino-Noonan and Verma-Naumoff-Le Marec.

Severe mental retardation and macroorchidism without mutation in the FMR1 gene.

Only one missense mutation, an Ile304Asn, has been reported in the fragile X gene (FMR1). This mutation is located in the second KH domain of FMR1, and has led to the discovery of the function of the FMR1 gene product as an RNA-binding protein. The patient carrying this mutation has profound mental retardation, macroorchidism, and an "acromegalic" face with prominent supraorbital ridges, enlarged jaw, heavy brow ridges, thick lips, and a broad nose. We have studied the possible involvement of FMR1 in two maternal half-brothers with a phenotype similar to that of the patient with the Ile304Asn mutation. Both brothers had an identical number of CGG repeats in the normal size-range, and shared the same maternal Xq27 haplotype. Southern blot analysis with two overlapping FMR1 cDNA clones, spanning the total FMR1 open reading frame, showed no major deletions, insertions, or gross rearrangements. Single-strand conformation pattern (SSCP) analysis of the KH domains showed no aberrant patterns. The total open reading frame of the FMR1 gene was cloned and sequenced, but no mutation was found. Northern blot analysis showed mRNA in the normal size-range, and immunocytochemistry on individual lymphocytes indicated that FMRP, the protein product of FMR1, was present. In conclusion, it is unlikely that FMR1 plays a role in the phenotype of this patient. Other genes may be responsible for the combination of mental retardation and macroorchidism.

Léri-Weill syndrome as part of a contiguous gene syndrome at Xp22.3.

We report on a mother and her 5-year old son, both with a terminal deletion of the short arm of the X chromosome. By molecular genetic analysis the breakpoint was located distal to steroid sulfatase gene. The boy manifested, due to nullisomy of this region, short stature (SHOX), chondrodysplasia punctata (ARSE), and mental retardation (putative mental retardation gene MRX 49). Short stature is present in mother and son, but both also had bilateral Madelung deformity, a key finding in the Léri-Weill syndrome. We discuss the phenotype in relationship to hitherto published cases with chromosomal aberrations and contiguous gene syndromes of Xp22.3.

Follow-up of monozygotic twins concordant for the Rett syndrome.

The clinical features and follow-up of monozygotic twins with the Rett syndrome (RS) are described. The twins are almost concordant in all clinical signs. This identity indicates a genetic cause of RS. A clinical follow-up confirmed the diagnosis.

Some problems in the genetics of X-linked mental retardation.

X-linked mental retardation has recently become one of the most interesting genetic anomalies. Studying this group of conditions has led to many insights into the mechanisms involved in normal and abnormal gene actions in humans. Since the early 1980s, the number of disease entities for which the responsible genes could be localized on the X chromosome has increased from year to year; at the Ninth International Workshop on Fragile-X-Syndrome and X-linked Mental Retardation, 199 such disease units were counted (Hamel, 1999). Conventionally, these units were subdivided into two groups: syndromal and non-syndromal types. The syndro- mal types are characterized by external features, neurological signs, and/or metabolic anomalies. The non-syndromal types do not show such specific features; here, the X-linked mode of inheritance is the only indicator. Due to the reduced reproduction of mentally severely retarded males, a relatively high fraction of new mutants among cases of a specific type must be expected. It cannot be the purpose of the present short article to review sufficiently well the entire field; this would require a complete book. Rather, it is our intention to point to some open problems and possible ways for their solution.

Symptomatic heterozygosity in the Ellis-van Creveld syndrome?

A 13-month-old girl with Ellis-van Creveld syndrome and her mildly affected father are described. We discuss whether the father is a symptomatic heterozygote of the Ellis-van Creveld syndrome or an untypical affected patient with Weyers' acrodental dysostosis.

Nonspecific X-linked mental retardation--a review.

Mental retardation, in particular the "X-linked" type, has interested geneticists for many years. An increasing number of affected families have been to genetic counselling centres, and an effort is being made to find clinical and cytogenetic methods so a reliable diagnosis can be made. This would enable the detection of carriers and the opportunity to offer prenatal diagnosis. Many questions remain regarding X-linked mental retardation, its causes, diagnosis, and prevention. In this article we try to give an overview about the status of our present knowledge and the questions to be answered in the future.

A monozygotic twin pair with Rett syndrome.

A five-year-old, monozygotic, Turkish female twin pair with Rett syndrome is described. The twins are almost completely concordant in all clinical signs. This observation suggests a genetic cause of Rett syndrome.

Prenatal enzymatic diagnosis and exclusion of Krabbe's disease (globoid-cell leukodystrophy) using chorionic villi in five risk pregnancies.

Galactosyl ceramide beta-galactosidase activity was determined in chorionic villi (CV) samples obtained between the 9th and 11th weeks of gestation from 5 women with pregnancies at risk for Krabbe's disease (globoid-cell leukodystrophy, KD). These enzyme activities were compared with those in controls, as well as with those in cultured amniotic fluid cells (AFC) from one of the five at-risk pregnancies and from 29 KD-risk pregnancies studied previously. The results of these CV enzyme analyses were such that one case of fetal KD was clearly diagnosable, one fetal genotype heterozygous for KD was presumed, and three normal fetal genotypes were suggested. The use of both uncultured and cultered CV can be recommended for prenatal KD testing, but AFC may continue to play an important role, too. Of the 58 prenatal KD tests we have evaluated since 1974, a positive diagnosis of Krabbe's disease was made (and confirmed after termination of pregnancy when feasible) in 23 which is significantly more than 25% of 58.

The secretor locus as a marker for prenatal prediction of myotonic dystrophy (DM).

To verify the reliability of secretor status for prenatal diagnosis of myotonic dystrophy (DM), 179 amniotic fluid samples were compared with saliva or urine samples of the infants by hemagglutination inhibition. While no discrepancies were observed, problems could arise with intermediate results. Additionally, secretor typing is only informative in 8.4% of patients.

[Transabdominal chorionic villi aspiration in the 1st and 2d trimester in 120 cases with reference to placental location]. / Transabdominale Zottenaspiration im 1. und 2. Trimenon in 120 Fällen unter Berücksichtigung der Placentalokalisation.

At the Gynecological Clinic of the Klinikum Ludwigshafen prenatal transabdominal diagnostic aspiration of villi was performed in 120 cases in the first and second trimesters between October 1986 and April 1988. The puncture was performed using a cannula system comprising a guide and an aspiration needle. The ultrasonographically controlled removal technique is described with special consideration of the procedure in cases with placental insertion in the posterior wall. Successful tissue removal (at least 5 mg of tissue) was achieved in 97.5% of the cases. Cytogenetic, biochemical, and molecular biologic studies were performed. The most frequent indication was to detect chromosome disorders in older mothers (74.2%). Such disorders were diagnosed in 4.2% of all cases and pregnancy was terminated in seven of them; the indications were aneuploidies, metabolic disease, or severe developmental anomalies detected by ultrasonography in normal karyotypes. In the remaining 113 pregnancies one miscarriage was seen nine weeks after aspiration of villi. On the basis of these results the abortion risk following transabdominal chorionic biopsy is 0.88% and is thus similar to that following amniocentesis.

Acrorenal syndrome in an adult--presentation with proteinuria, hypertension, and glomerular lesions.

Acrorenal syndrome is characterized by central longitudinal axis defects of the limbs, ie, split hand and/or foot. Associated renal lesions described so far comprise agenesis, bilateral hypoplasia (originally diagnosed as oligomeganephronia), and duplication abnormalities. The case of a 29-year-old patient with split hand resulting from bilateral aplasia of the third phalanges associated with dysplasia of the third and fourth metacarpals is reported. In addition, the following lesions were noted: hypoplasia of the middle phalanx of the fifth toe, arched palate, pectus excavatum, hypoplastic mammilae, scoliosis, and congenital hip dislocation. The patient presented with hypertension, modest reduction of glomerular filtration, proteinuria, microhematuria, cylindruria, and moderate harmonic hypoplasia of the right kidney on angiography. Glomeruli had no immune deposits on immunohistology. Light microscopy showed widening of the mesangial axis, focal segmental glomerular sclerosis, and renal interstitial fibrosis with occasional foam cells. This case shows that the spectrum of renal abnormalities in the acrorenal syndrome is wider than previously noted.

Molecular studies of an X;Y translocation chromosome in a woman with deletion of the pseudoautosomal region but normal height.

A translocation chromosome in a woman with the karyotype 46,X,der(X)t(X;Y)(p22.3; q11.2) was investigated by FISH and STS analysis with molecular probes derived from the sex chromosomes. Due to the partial deletion of the short arm pseudoautosomal region (PAR1) from DXYS14 to DXYS147 in the translocation chromosome, the proband is hemizygous for the gene responsible for growth control (SS) located in this region, yet does not show growth retardation. Molecular analysis of the Yq arm of the translocation chromosome revealed the presence of markers DYS273 to DYS246 harboring the hypothesized growth control gene critical region (GCY) on Yq, thereby placing the deletion breakpoint between markers DYS11 and DYS273. These results suggest that the Y-specific growth gene GCY on Yq compensates for the missing growth gene SS on Xp22.3.