Spondylo-meta-epiphyseal dysplasia, short limb-abnormal calcification type, is a rare autosomal recessive disorder of the skeleton characterized by disproportionate short stature with narrow chest and dysmorphic facial features. The skeletal manifestations include platyspondyly, short flared ribs, short tubular bones with abnormal metaphyses and epiphyses, severe brachydactyly, and premature stippled calcifications in the cartilage. The abnormal calcifications are so distinctive as to point to the definitive diagnosis. However, they may be too subtle to attract diagnostic attention in infancy. Homozygous variants in DDR2 cause this disorder. We report on a 5-year-old girl with the classic phenotype of SMED, SL-AC in whom a novel homozygous nonsense mutation in DDR2 was detected using exome sequencing.

Anauxetic dysplasia (AAD, OMIM 607095) is a rare skeletal dysplasia inherited as an autosomal recessive trait, which is caused by mutations in RMRP and allelic to a more common disorder, cartilage hair hypoplasia (CHH). CHH is a multi-system disorder with a variety of extraskeletal changes. Whereas AAD is a bone-restricted disorder with a more severe skeletal phenotype: affected individuals are extremely short and complicated by orthopedic morbidity, and the radiological changes include modification of the vertebral bodies and epiphyseal dysplasia of the hip, as well as generalized metaphyseal dysplasia and severe brachydactyly. Recently, genetic heterogeneity for AAD was proposed, because a familial case (two affected sibs) with an AAD-identical phenotype had compound heterozygous mutations in POP1, encoding a molecule functionally related to the gene product of RMRP. We report here a 5-year-old boy with the same phenotype born to a consanguineous couple. We identified a novel homozygous POP1 mutation (c.1744C>T, p.P582S) in the boy and the heterozygosity in the parents. It may be rational to coin the POP1-associated skeletal phenotype AAD type 2. © 2016 Wiley Periodicals, Inc.

A 35-year-old woman was admitted to our hospital for evaluation of end-stage renal failure. Diagnostic imaging, including ultrasonography and magnetic resonance imaging, showed polycystic kidneys and peribiliary hepatic cysts, but the renal cysts were isointense and her kidneys were smaller than the end-stage kidneys of patients with autosomal dominant polycystic kidney disease. Glomerulocystic kidney disease was diagnosed by renal biopsy. Clinical examination revealed findings such as a missing maxillary canine, lingual anomalies, and brachydactyly. Genetic testing gave a diagnosis of orofaciodigital syndrome type 1 with a 5 nucleotide deletion indicating a frameshift mutation in exon 9. The patient's mother had the same mutation and similar clinical findings. This case is useful for understanding kidney and liver involvement in orofaciodigital syndrome type 1.

The femoral facial syndrome (FFS) is a rare congenital anomaly syndrome characterized by bilateral femoral hypoplasia and facial dysmorphism. The etiology of FFS is currently unknown but maternal/gestational diabetes has been proposed as a strong risk factor for syndromic femoral hypoplasia. In affected children born to non-diabetic mothers, a genetic contribution to FFS is suspected; however, no chromosomal anomalies or gene mutations have been identified so far. Here, we report on a girl with FFS and a de novo complex chromosome rearrangement of terminal chromosome 2q37.2. Radiographs of the pelvis and lower limbs showed bilateral shortening and bowing of the femur and radiographs of hands and feet revealed a brachydactyly type E (BDE). Using high resolution array-CGH, qPCR, and FISH, we detected a ~1.9 Mb duplication in the chromosomal region 2q37.2 and a ~5.4 Mb deletion on chromosome 2q37.3 that were absent in the parents. The duplication contains six genes and the deletion encompasses 68 genes; the latter has previously been shown to cause BDE (through haploinsufficiency for HDAC4) but not femoral hypoplasia. Therefore, we propose that the duplication 2q37.2 could be causative for the femur phenotype. To the best of our knowledge, our report is the first to propose a genetic cause in a case of FFS.