Multi-disease panel for the Miniature Schnauzer grouping six molecular tests: Charcot-Marie-Tooth neuropathy (CMT), susceptibility to the Mycobacterium avium complex (MAC), congenital myotonia, persistent Müllerian duct syndrome (PMDS), type B1 progressive retinal atrophy (B1-PRA, HIVEP3) and spondylocostal dysostosis (comma defect). It combines neuromuscular, immunological, muscular, reproductive developmental, ocular and vertebral conditions.

Applicable breed: Miniature Schnauzer. Reliable country-specific frequencies for the breeding population are not published systematically (limited data). Congenital myotonia and B1-PRA are more widespread; MAC, CMT and comma defect have a smaller case load.

- Distal muscle weakness and atrophy, hypo/areflexia, signs of peripheral neuropathy (CMT)
- Severe and recurrent infections by environmental mycobacteria (MAC)
- Muscle stiffness after rest that subsides with exercise, myotonia (congenital myotonia)
- Male with retained uterus/oviducts, cryptorchidism, infertility or prostatic disorders (PMDS)
- Reduced night vision and progressive retinal atrophy (B1-PRA)
- Severe vertebral deformity, scoliosis, fused/absent ribs in puppies (comma defect)

The various conditions in the panel were characterised independently. B1-PRA of the Miniature Schnauzer was associated with the HIVEP3 gene. Congenital myotonia of the breed was associated with the CLCN1 gene. Mycobacterial susceptibility (MAC) and CMT have been described in the breed. Comma defect (spondylocostal dysostosis) has been reported in Miniature Schnauzer puppies. CMT of the Miniature Schnauzer is associated with SBF2 (Granger 2019), MAC susceptibility with CARD9 (Mizukami 2024), PMDS with AMHR2 (Wu 2009; Smit 2018), comma defect with HES7 (Willet 2015) and myotonia with CLCN1 (Rhodes 1999; Bhalerao 2002): the six conditions in the panel have a published molecular basis.

- Genotype breeding animals before mating; the panel covers six conditions in a single sample
- For the recessive conditions (CMT, MAC, myotonia, B1-PRA, comma defect): do not mate two carriers — 25% risk of affected homozygotes; carrier×clear is safe for offspring intended for breeding if tested
- For PMDS: assess the status before breeding with affected lines; communicate the risk to buyers of males
- After a confirmed clinical case, do not repeat the parental mating and communicate the status to the buyer

Verify the exact panel offered by each laboratory. Congenital myotonia is confirmed by electromyography and molecular testing. CMT is confirmed by electrophysiology and nerve biopsy. MAC requires immunological and microbiological diagnosis. PMDS is suspected in males with cryptorchidism/infertility and is confirmed by imaging and molecular testing. B1-PRA requires ocular examination (ECVO). Comma defect is diagnosed by radiography in puppies.

1. Granger N et al. 2019, neuropatía desmielinizante CMT4B2 por SBF2 en Schnauzer miniatura (PMID 31772832)
2. Mizukami K et al. 2024, susceptibilidad a MAC por deleción en CARD9 en Schnauzer miniatura (PMID 38710903)
3. Rhodes TH et al. 1999, mutación missense de CLCN1 y miotonía congénita recesiva (PMID 10452529)
4. Bhalerao DP et al. 2002, mutación de miotonía congénita en Schnauzer miniatura y ancestro portador común (PMID 12371774)
5. Kaukonen M et al. 2020, PRA tipo B del Schnauzer miniatura e HIVEP3 (PMID 32150541); Murgiano L et al. 2019, variante PPT1 (PMID 30541930)
6. Wu X et al. 2009, PMDS por AMHR2 (PMID 18723470); Smit MM et al. 2018, prevalencia AMHR2 (PMID 29194807)
7. Willet CE et al. 2015, deleción exónica de HES7 y disostosis espondilocostal AR en Schnauzer miniatura (PMID 25659135)