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Biomedical subjects

A Schinzel

Publications and source records attributed to A Schinzel.

At least 145 records · Page 8Linked to original sources
PubMed1991

[Autosomal dominant hereditary retinopathia pigmentosa with genetic heterogeneity].

There is considerable clinical variability in autosomal dominant retinitis pigmentosa (ADRP). The underlying biochemical defect had remained unknown until recently, so that it was not possible to determine the primary cause(s) of this phenotypic diversity. Recently, different point mutations and base pair deletions have been identified in the rhodopsin gene in a proportion of patients with ADRP, providing convincing evidence for allelic genetic heterogeneity in this disease. We screened a total of 65 patients with ADRP in Germany, Austria, and Switzerland for the presence of the point mutations described recently at codons 58 and 347 in patients in the USA. Our results show that the frequency of point mutations at codon 347 in the patients studied here is about 3%, a figure similar to that found in the USA. The frequency of the mutation at codon 58 seems to be generally low. The identification of patients with point mutations in the rhodopsin gene offers the possibility, for the first time, of studying the correlation between genotype and disease phenotype.

Chromosome Aberrations↗
PubMed1990

Prenatal diagnosis of X-linked hypohidrotic ectodermal dysplasia by linkage analysis.

Prenatal diagnosis of X-linked hypohidrotic ectodermal dysplasia was previously performed by the direct histological analysis of fetal skin obtained by late second trimester fetoscopy. The recent gene mapping of the locus for the disorder to the region of Xq11-21.1 now permits the indirect prenatal diagnosis of the disorder by the method of linkage analysis, based on closely linked marker loci, during the first trimester of pregnancy. We report the prenatal diagnosis of a male fetus with a high probability of the disorder by a linkage analysis utilizing restriction fragment length polymorphisms at the DXS159, PGK1, and DXS72 loci, from a DNA sample obtained by a chorionic villus biopsy at 9 weeks gestation. After further counseling, the pregnancy was terminated but the diagnosis could not be confirmed by histological analysis, even though analysis of skin samples by light and electron microscopy showed lack of hair germs, primary dermal ridges, and sweat gland primordia, due to the early developmental stage of the fetus. The use of DNA-based linkage analysis now offers the opportunity for an earlier diagnosis of X-linked hypohidrotic ectodermal dysplasia by a method other than fetal skin sampling. However, families must also fully understand the present limitations of the method prior to undertaking the procedure.

Adult↗
PubMed1990

Short stature, brachydactyly, small ears, and a pattern of minor anomalies in brother and sister born to consanguineous parents: a hitherto unreported syndrome?

A 13-year-old boy and his 28-year-old sister had short stature, obesity, and a pattern of minor anomalies including a sloping, narrow forehead; small ears; a narrow nose with prominent bridge and long septum; short upper lip; receding mandible; and short limbs with brachydactyly and clinodactyly of little fingers. The boy also had hypoplastic external genitalia and elevated FSH. Both are of normal intelligence. There is remote consanguinity of the (normal) parents. The 2 sibs probably represent a hitherto un-recognized syndrome of possibly autosomal recessive inheritance.

Adolescent↗
PubMed1990

Phocomelia and additional anomalies in two sisters.

Two daughters of non-consanguineous normal parents had phocomelia of both lower extremities with 4-toed feet. The older sister also had phocomelia of the left upper extremity with 5 finger rays; she died immediately after birth. Autopsy disclosed a congenital diaphragmatic hernia, common mesentery and agenesis of the gallbladder, and normal female genitalia. In addition, the younger sister showed a bony skull defect, diastasis recti, agenesis of the uterus and agenesis or atresia of the vagina, hypoplasia of the sacrum and hypo/dysplasia of the pelvic bones. Her growth and mental development were normal. The patterns of anomalies of the two sisters do not fit into any of the syndromes featuring phocomelia; there was no prenatal exposure to thalidomide or any other possible teratogen.

Abnormalities, Multiple↗
PubMed1990

[Iniencephaly: prenatal and postnatal findings].

A 33-year-old para-3 was admitted in the 33rd week of gestation because of a suspected foetal anomaly. Ultrasound examination showed polyhydramnios, exaggerated cervico-thoracic lordosis and significant shortening of the spine because of a reduced number of vertebrae. The facial profile was flat, the foetal movements were rare and slow, and the extremities normal. A biopsy of the placenta revealed a normal female karyotype. Based on ultrasound examination, the diagnosis of iniencephaly was made. Because of the fatal prognosis of this malformation, labour was induced at 35 weeks of gestation. The patient delivered spontaneously. The infant died after 90 minutes. The postmortem examination confirmed the diagnosis of iniencephaly. Iniencephaly is a very rare malformation comprising a bone defect at the occiput, malformation of the cervical and thoracic vertebrae, spina bifida, and retroflexion of the head. The aetiology is not clear. 90% of the probands are female. The malformation is incompatible with survival after birth.

Abnormalities, Multiple↗
PubMed1990

[X-chromosomal hereditary night blindness: detection of carriers by segregation analysis with linked DNA markers].

Congenital stationary night blindness is a rare disease with autosomal dominant, autosomal recessive, or X-linked recessive inheritance. The X-chromosomal form is frequently associated with myopia. Female carriers have no symptoms of visual impairment and therefore cannot be identified clinically. The close link recently described between the disease locus and the DXS7 locus, mapped in Xp11.3, as well as other marker loci from this chromosomal region, permits indirect genotype analysis and thus identification of the carriers; with the information thus obtained, improved genetic counseling is possible. The authors studied a large Swiss family with the X-linked trait. Segregation analysis was performed with DXS7 as well as two flanking markers, DXS255 and OTC. It was thus possible to determine the degree or probability of several female members of the family being carriers.

Chromosome Banding↗
PubMed1990

Familial congenital laryngeal abductor paralysis: different expression in a family with one male and three females affected.

A brother and two sisters of remotely consanguineous parents had congenital laryngeal abductor paralysis and moderate mental retardation. In the two older sibs, mental deficiency could have resulted from birth asphyxia, but the youngest girl was already microcephalic at birth and had no apparent asphyxia. The mother, who was healthy and of normal intelligence, was found on laryngoscopy to have unilateral laryngeal abductor paralysis. This is the first family with both mentally retarded and nonretarded affected members with congenital laryngeal abductor paralysis. Inheritance is most likely autosomal dominant with variable expression, but autosomal recessive inheritance, with both parents carriers and the mother an affected homozygote, and X linked inheritance are also possible.

Consanguinity↗
PubMed1990

Partial trisomy of chromosome 18 (pter----q12) following a familial 18;21 translocation rcp(18;21)(q12;q11).

A 1-year-old boy with trisomy 18 (pter----q12) following a paternal balanced translocation revealed microcephaly, a pattern of minor dysmorphic features including upslanting narrow palpebral fissures, receding forehead, large nose and receding mandible, cryptorchidism, flexion contractures of fingers, a cardiac malformation and moderate mental retardation. While pure trisomy 18p generally goes along with a near-normal phenotype, additional trisomy of only a short segment of the proximal long arm 18 has a distinct negative influence on the phenotype, as seen in our proband.

Abnormalities, Multiple↗
PubMed1990

Skeletal muscular changes in Pena-Shokeir sequence.

Histologic examination of the skeletal muscles in 8 fetuses and newborn patients with the Pena-Shokeir sequence revealed only minor nonspecific changes which could not be ascribed to any of the well defined myopathies. Muscle fiber diameters were increased in 2 out of 5 patients examined. No significant malformations of inner organs were found at autopsy. It is concluded that fetal hypokinesia due to skeletal muscular lesions might be responsible for both the pulmonary hypoplasia and the deformations of the face and extremities in all cases of this investigation.

Birth Weight↗
PubMed1990

Anophthalmia in a retarded girl with partial trisomy 4p and 22 following a maternal translocation, rcp(4;22)(p15.2;q11.2).

An 18-year-old girl displayed left anophthalmia and right severe microphthalmia, mild dysmorphic features of facies and distal limbs, a right preauricular pit, and moderate mental retardation. She was trisomic for the distal part of the short arm of chromosome 4 and the proximal segment of chromosome 22, due to unbalanced 3:1 segregation of a maternal 4;22-translocation. Anophthalmia is a rare finding in chromosome aberrations in general, and particularly in patients not featuring other severe malformations and severe to profound mental retardation.

Adult↗
PubMed1990

Application of linked DNA markers to screening families with multiple endocrine neoplasia type 2A.

There now exists a set of tightly linked markers to the gene causing multiple endocrine neoplasia type 2A. In this report we discuss the use of these markers for early and accurate prediction of gene carrier status in three different families. Factors that influence the probability of obtaining useful information with DNA markers are available family size, in particular the number of available affected individuals, and the extent of clinical and biochemical screening in the family. At present, DNA analysis has about a 3% risk of misdiagnosis; this risk is even lower if it is used in conjunction with the pentagastrin stimulation test for C-cell hyperplasia. With the combined tests, an individual at age 20 years may be scored as carrier or not with an estimated accuracy of 99%.

Adolescent↗
PubMed1990

[Dubowitz syndrome: a dysmorphism syndrome with developmental delay, transitory short stature, hyperactive behavior and atopic dermatitis].

The Dubowitz-syndrome, a rare, autosomal-recessive condition, was seen in a 6-year-old female patient. Verbal, fine motor, and social development were severely retarded. Behavioral disturbances, predominantly hyperactivity were apparent. Short stature of unknown origin became evident during infancy and early childhood. Atopic dermatitis and specific sensitivity to inhalant and nutritive allergens was found. A pattern of minor anomalies included inner epicanthic folds, hypertelorism, flat nasal bridge, globular nasal tip, coarse lips, and retrogenia as well as pes planovalgus, and a sacral dimple.

Abnormalities, Multiple↗