Study of a family with Cerebrotendinous Xanthomatosis. No HLA linkage, but an informative recombination between HLA-B and Bf

A large family with three children affected with the autosomal recessive disease of Cerebrotendinous Xanthomatosis (CTX) was studied for class I (HLA-A,B,C) and class II antigens (HLA-DR,D,SB), properdin factor B and glyoxalase. The extensive typing revealed an informative cross-over between HLA-B and Bf, indicating that Bf is located centromeric to the HLA-B locus and segregated in this family with HLA-D/DR. The parents in this family were first cousins and their parents were also first cousins. Three of their four haplotypes share B14, BfS, DR1, Dx and SB4 and may be identical by descent. The three affected children carried among them all four parental haplotypes, indicating that close linkage of the CTX locus to HLA is unlikely.     

Structural development of the feline mental nerve

The qualitative and quantitative structural development of the feline mental nerve (MN), a branch of the inferior alveolar nerve (IAN), was studied by electron microscopy from 40 days postconception (dpc) (about 2 weeks before birth) to 11 years after birth. Myelination was initiated at 40–45 dpc. At 2 months after birth de novo myelination was completed, and the larger myelinated axons had achieved a fully differentiated nodal-paranodal morphology. Size growth of myelinated axons continued until 6 months, when a bimodal size distribution between 1 and 12 months was established. When compared to the IAN, the MN contained a higher proportion of unmyelinated axons. Age-related signs of axon degeneration, which previously were recorded in the IAN, were lacking in the MN. This suggests that senescent IAN axon degeneration is related to dental rather than to cutaneous MN branches.     

Partial 18 trisomy (with 47 chromosomes) resulting from a familial maternal translocation.

A newborn female infant presented with the classical picture of 18 trisomy syndrome. Her karyotyping was 47,XX,+der(18)t(12;18)(q24;q21)mat. The mother was a balanced reciprocal translocation carrier and so too was one of the two maternal uncles of the proposita, indicating that the translocation was already present in one of the grandparents who were not available for examination. This family suggests that triplication of the distal part of the long arm of chromosome 18 is not necessary to produce Edwards' syndrome.     

Polysyndactyly and Marfan''s syndrome

An Egyptian Jewish family in which polysyndactyly is transmitted through four generations with 17 affected individuals is presented. The malformation is caused by an autosomal dominant gene with full penetrance and variable expressivity. In the newborn propositus the gene was fully expressed producing polysyndactyly of both hands and both feet. The mother had polysyndactyly of the feet but only syndactyly of the third and fourth fingers of the right hand and a post minimi on the left hand. In addition she had Marfan's syndrome due to a new mutation and transmitted Marfan's syndrome to one of her daughters who did not have polysyndactyly. Apparently the association of Marfan's syndrome with polysyndactyly has not been previously described.     

Familial translocation 15/22. A possible cause for abortions in female carriers

A familial Robertsonian translocation 15/22 was ascertained through a female carrier whose four pregnancies ended in missed abortions. Eleven 15/22 translocation carriers were detected in three generations among 23 family members investigated. The four proven female carriers, apart from the proposita, have miscarried seven out of 14 pregnancies. The kindred suggests that the 15/22 translocation in female carriers may cause an increased risk for miscarriage.     

Familial thyroglossal duct cyst

Thyroglossal duct cysts are common congenital abnormalities or developmental field defects, usually detected in early childhood. Despite their frequent occurrence, familial patterns are rare. We report on two new families with thyroglossal duct cysts. In the first family three siblings were involved, while in the second one, father and son were affected. This trait may be autosomal recessive or possibly multifactorial, as the first family would indicate, and also autosomal dominant, as the second family would suggest.     

In vivo NGF deprivation reduces SNS expression and TTX-R sodium currents in IB4-negative DRG neurons

Recent evidence suggests that changes in sodium channel expression and localization may be involved in some pathological pain syndromes. SNS, a tetrodotoxin-resistant (TTX-R) sodium channel, is preferentially expressed in small dorsal root ganglion (DRG) neurons, many of which are nociceptive. TTX-R sodium currents and SNS mRNA expression have been shown to be modulated by nerve growth factor (NGF) in vitro and in vivo. To determine whether SNS expression and TTX-R currents in DRG neurons are affected by reduced levels of systemic NGF, we immunized adult rats with NGF, which causes thermal hypoalgesia in rats with high antibody titers to NGF. DRG neurons cultured from rats with high antibody titers to NGF, which do not bind the isolectin IB4 (IB4(-)) but do express TrkA, were studied with whole cell patch-clamp and in situ hybridization. Mean TTX-R sodium current density was decreased from 504 +/- 77 pA/pF to 307 +/- 61 pA/pF in control versus NGF-deprived neurons, respectively. In comparison, the mean TTX-sensitive sodium current density was not significantly different between control and NGF-deprived neurons. Quantification of SNS mRNA hybridization signal showed a significant decrease in the signal in NGF-deprived neurons compared with the control neurons. The data suggest that NGF has a major role in the maintenance of steady-state levels of TTX-R sodium currents and SNS mRNA in IB4(-) DRG neurons in adult rats in vivo.     

Severe lower limb malformation associated with other deformities and death in infancy in two brothers.

Two brothers with severe and rare lower limb malformations but normal upper limbs are described. Both brothers had glans hypospadias and they died in early infancy. In the first brother the limb malformation was a severe deformity of the right foot which was split and of rockerbottom shape with oligosyndactyly. In the second brother the right limb below the knee was more severely deformed while only the toes were involved in the left limb. Details of the clinical and pathological findings are described. The most likely mode of inheritance of this rare syndrome is autosomal recessive or X-linked recessive with variable expressivity.