Defining the phenotype in an autosomal recessive cutis laxa syndrome with a combined congenital defect of glycosylation.

Autosomal recessive cutis laxa is a genetically heterogeneous condition. Its molecular basis is largely unknown. Recently, a combined disorder of N- and O-linked glycosylation was described in children with congenital cutis laxa in association with severe central nervous system involvement, brain migration defects, seizures and hearing loss. We report on seven additional patients with similar clinical features in combination with congenital disorder of glycosylation type IIx. On the basis of phenotype in 10 patients, we define an autosomal recessive cutis laxa syndrome. The patients have a complex phenotype of neonatal cutis laxa, transient feeding intolerance, late closure of the fontanel, characteristic facial features including down-slanting palpebral fissures, short nose and small mouth, and developmental delay. There is a variable degree of the central nervous system involvement and variable systemic presentation. The biochemical analysis using transferrin isoelectric focusing gives false negative results in some of the youngest patients. Analysis of the apolipoprotein C-III isoelectric focusing, however, is diagnostic in all cases.

Clinical implications of atypical chromosome abnormalities diagnosed prenatally.

OBJECTIVE: To determine the frequency of atypical aneuploidy resulting from prenatal testing and assess the implications of these diagnoses on prenatal decision making. METHODS: We reviewed all amniotic fluid and chorionic villus samples obtained between January 1994 and September 1997 and grouped the abnormal cases into typical or atypical subcategories. This distinction was based upon whether the diagnosis provided a straightforward range of prognoses or an ambiguous clinical implication. Results were stratified by sample source to determine whether atypical aneuploidy was more commonly seen in cultures of chorionic villi or amniocytes. We also evaluated the influence of ultrasound findings on prenatal decision making in atypical aneuploid cases. RESULTS: Of 2960 samples, 134 were abnormal (4.4%), with 27 of 134 abnormalities (20%) representing atypical aneuploidies. The percentages of chorionic villus and amniocentesis cases complicated by atypical aneuploidy (22% and 78%, respectively) were consistent with the distribution of procedures in the entire study. Ultrasound abnormalities did not invariably prompt a decision to terminate pregnancy (only two terminations of six fetuses with congenital malformation), whereas atypical karyotypes led to termination even in the presence of normal-appearing fetal anatomy (five terminations of 21 without malformations; P = .63). CONCLUSION: The frequency of atypical aneuploidy resulting from prenatal diagnosis was approximately 1.0%, and these cases represented 20% of all abnormal karyotypes observed. The ambiguity conferred by atypical aneuploidy can influence a family's decision making, even in the presence of normal ultrasound findings.

Dysplasia of the knee associated with the syndrome of thrombocytopenia and absent radius.

We studied the cases of twenty-one patients with the syndrome of thrombocytopenia and absent radius. Patients with this syndrome usually have associated intra-articular dysplasia of the knee joint bilaterally, causing genu varum and a flexion and torsional deformity that become manifest in the first or second year of life. Usually there is progression of the deformities during growth and therefore treatment with braces or operations, or both, will frequently be needed. Despite correctional osteotomy, the varus angulation and internal tibial rotation have a natural tendency to recur, possibly because of the intra-articular deformity that involves the femoral and tibial condyles. After skeletal maturity has been reached, minimum progression of the deformity has been observed.

Fetal alcohol syndrome in dizygotic twins.

A pair of fraternal twins with stigmata of the fetal alcohol syndrome are described. Apparently differences in susceptibility to the dysmorphogenic influence of ethanol caused one twin to be more severely affected than the other one. Both infants are growing poorly postnatally, and both are at risk for retarded development. Any evidence of the fetal alcohol syndrome, however, subtle, should be considered a warning of possible future developmental delay.

Deletion of band 5q21 in association with a de novo translocation involving 2p and 5q.

A six month old girl with developmental delay and dysmorphic features was found to have a translocation involving 2p and 5q as well as a deletion of band 5q21.

Maternal UPD 20 in an infant from a pregnancy with mosaic trisomy 20.

Maternal uniparental disomy (UPD) 20 was found in a 35-month-old girl, the product of a pregnancy complicated by a prenatal diagnosis of mosaic trisomy 20. Phenotypic abnormalities included pre- and postnatal growth failure, microcephaly, minor dysmorphic features and psychomotor developmental delay. Chromosomal analysis on cord blood revealed only a normal 46,XX karyotype. Microsatellite analysis of 27 chromosome 20 loci confirmed maternal UPD for all 11 informative markers. Maternal heterodisomy was detected in two and maternal isodisomy in three loci. In the remaining six loci, a non-informative maternal UPD pattern was displayed, as mother and proband are homozygous for the same allele. To our knowledge this is the first reported case of maternal disomy 20 with normal karyotype ascertained by a mosaic trisomy 20 pregnancy.

Computerized tomography and ultrasound in the diagnosis of cerebro-hepato-renal syndrome of Zellweger.

Renal cortical cysts were demonstrated by computerized tomography and ultrasound in a patient with cerebro-hepato-renal syndrome who did not have patellar calcifications.