Smoc1 and Smoc2, members of the SPARC family of genes, encode signaling molecules downstream of growth factors such as the TGF-β, FGF, and PDGF families. Smoc1 has been implicated in playing a crucial role in microphthalmia with limb anomalies in humans and mice, while Smoc2 deficiency causes dental developmental defects. Although developmental cytokines/growth factors including TGF-β superfamily have been shown to play critical roles in postnatal spermatogenesis, there are no reports analyzing the spatial and temporal expression of Smoc1 and Smoc2 in the postnatal testis. In this study, we investigated the mRNA and protein expression of Smoc1 and Smoc2 in neonatal, juvenile, and adult mouse testes by RNA in situ hybridization, immunofluorescence, and single-cell RNA-seq analysis. We show that Smoc1 and Smoc2 have distinct expression patterns in male germ cells: Smoc1 is more highly expressed than Smoc2 in the germline. In contrast, Smoc2 is highly expressed in testicular somatic cells from neonatal to juvenile stages. The Smoc2-expressing cells then switch from somatic cells to germ cells in adults. Thus, although SMOC1 and SMOC2 proteins are structurally very similar, their spatial and temporal expression patterns in the postnatal testis differ significantly, suggesting their distinct roles in reproduction.

Microphthalmia is a rare autosomal recessive condition commonly known as Waardenburg anophthalmia syndrome (WAS) or oculo-acromal formation syndrome (MIM#206920). Here, we report the case of a woman whose fetal ultrasonography at 12 weeks of pregnancy revealed multiple fetal abnormalities. These included the absence of the left upper limb, an unclear display of the right orbit, a visible maxillary space, and a round, echoless appearance measuring 4 mm in diameter in the middle of the forehead. There was also a significant echo in the sac wall. The possibility of a frontal meningocele or a proboscis-like nose was considered. The fetus was delivered with absence of the left upper limb, absence of the right eye, a cleft lip on the right side, and a milky white sac with a diameter of 5 mm on the forehead after the pregnancy was terminated at the hospital. Pathological investigation revealed a mature cystic teratoma. The conclusion was microphthalmia with limb anomalies (MLA) after missing limbs, absence of eyes, and cleft lip were input into the Online Mendelian Inheritance in Man database. The case was diagnosed with fetal microphthalmia with limb anomalies and an interfrontal teratoma. In this case, the entire exon analysis was not conducted, and as a result, the final diagnosis remains unclear. Based exclusively on the phenotype of the induced fetus, MLA was diagnosed. It is proposed that cases satisfying the requirements for a pathological diagnosis should undergo a pathological examination to establish a definitive diagnosis.

Trio exome sequencing was performed on a fetus with bilateral mesomelia of the lower limbs with significant angulation of the tibial bones, micrognathia and hypertelorism detected on ultrasound scan at 19 + 0 weeks gestation. The couple is consanguineous. A homozygous pathogenic frameshift variant in the SMOC1 gene (c.339_340del p.(Phe114Cysfs*40)) was detected and both parents were shown to be heterozygous. Pathogenic variants in the SMOC1 gene are associated with microphthalmia with limb anomalies which multidisciplinary team discussion determined to be causal of the scan anomalies detected. The fetus was also a compound heterozygote for CYP21A2 pathogenic variants, confirming a second diagnosis of non-classical congenital adrenal hyperplasia, which was felt incidental to the scan findings. The risk that this couple's next pregnancy would be affected by either of these disorders is 1 in 4 (25%) and demonstrates the importance of genetic diagnoses for the family and implications for future pregnancies.

Microphthalmia with limb anomalies is a rare, autosomal recessive, multiple congenital anomaly syndrome. Patients with this syndrome particularly present with monocular or bilateral anophthalmia/microphthalmia and distal limb anomalies. However, details regarding associated spinal deformities have not been fully elucidated. A 12-year-old girl initially presented with progressive scoliosis, who was previously diagnosed with microphthalmia with limb anomalies. However, 4 years after the initial visit, the scoliosis deformity gradually progressed. The patient and family requested the surgical treatment to preserve standing/sitting balance. She was diagnosed with microphthalmia with limb anomalies and progressive scoliosis. A posterior corrective fusion surgery (including a pelvic fusion) was performed to prevent future standing/sitting imbalance. Significant improvement of spinal deformity was observed, with no adverse events. This report demonstrated a case of progressive scoliosis associated with microphthalmia with limb anomalies. A posterior corrective spinal fusion was effective to preserve standing/sitting balance. To the best of our knowledge, this is the first report of surgical treatment of progressive scoliosis associated with microphthalmia with limb anomalies.