Autosomal recessive spastic paraplegia (SPG45) with mental retardation maps to 10q24.3-q25.1.

Hereditary spastic paraplegias (HSPs) are characterized by progressive spasticity in the lower limbs. They are clinically heterogeneous, and pure forms as well as complicated forms with other accompanying clinical findings are known. HSPs are also genetically heterogeneous.

Homozygous WNT10b mutation and complex inheritance in Split-Hand/Foot Malformation.

Split-Hand/Foot Malformation (SHFM) is a complex limb malformation affecting the central rays of the autopod. We studied a large consanguineous kindred afflicted with autosomal recessive SHFM. Twelve affected members had central feet reductions with or without hand involvement while the remaining one had the mildest phenotype and atypical SHFM.

A deletion in DRCTNNB1A associated with hypomyelination and juvenile onset cataract.

Hypomyelination and congenital cataract is a recently reported autosomal recessive white matter disorder characterized by hypomyelination of the central and peripheral nervous systems, progressive neurological impairment and congenital cataract and caused by mutations in gene DRCTNNB1A. Here we report a large intragenic deletion that does not lead to congenital cataract in all of the patients in an afflicted family. The clinical phenotypes described for five patients broaden the phenotype of the disease and indicate that congenital cataract is not an essential criterion for differential diagnosis.

Mutations in SLC34A2 cause pulmonary alveolar microlithiasis and are possibly associated with testicular microlithiasis.

Pulmonary alveolar microlithiasis (PAM) is a rare disease characterized by the deposition of calcium phosphate microliths throughout the lungs. We first identified a PAM locus by homozygosity mapping to 4p15, then identified, by a candidate-gene approach, the gene responsible for the disease as SLC34A2 (the type IIb sodium-phosphate cotransporter gene), which is involved in phosphate homeostasis in several organs. We identified six homozygous exonic mutations in the seven unrelated patients with PAM we studied.

Severe form of Cockayne syndrome with varying clinical presentation and no photosensitivity in a family.

We report six patients with Cockayne syndrome type B without photosensitivity. The patients are from the same inbred family and exhibit variable clinical features. The main clinical manifestations were progressive encephalopathy including intracranial calcification and white-matter lesions, dwarfism without growth hormone deficiency, senile appearance, mental and motor retardation, atrophy of subcutaneous fat tissue, severe pectus carinatus, and spasticity.

Identification of a locus for an autosomal recessive hyaline body myopathy at chromosome 3p22.2-p21.32.

Hyaline body myopathy is a rare congenital disease with distinctive histopathological features. We performed homozygosity mapping in a family with two affected sibs and identified a gene locus with a maximum homozygosity region of 5.35 centi Morgans or 5.

Is the novel SCKL3 at 14q23 the predominant Seckel locus?

Seckel syndrome (SCKL) is a rare disease with wide phenotypic heterogeneity. A locus (SCKL1) has been identified at 3q and another (SCKL2) at 18p, both in single kindreds afflicted with the syndrome. We report here a novel locus (SCKL3) at 14q by linkage analysis in 13 Turkish families.