M
- MASS Phenotype
- MASS syndrome
- MAT deficiency
- MCAD Deficiency
- MCDS
- MCT8-specific Thyroid Hormone Cell Transporter Deficiency
- MDMHB
- MDST
- MECP2 duplication syndrome
- MELAS
- MERRF
- MERS
- Mac Dermot Winter syndrome
- Macrocephaly, macrosomia, facial dysmorphism syndrome
- Macrocephaly-Capillary Malformation
- Macroepiphyseal dysplasia with osteoporosis, wrinkled skin, and aged appearance
- Macrosomia with lethal microphthalmia
- Macrosomia, obesity, macrocephaly, ocular abnormalities
- Macrothrombocytopenia and progressive sensorineural deafness
- Macrothrombocytopenia progressive deafness
- Macular Dystrophy
- Macular coloboma, bilateral, with hypercalciuria
- Macular dystrophy, concentric annular
- Macules hereditary congenital hypopigmented and hyperpigmented
- Madelung's disease
- Madokoro Ohdo Sonoda syndrome
- Maffucci syndrome
- Majeed syndrome
- Majewski Osteodysplastic Primordial Dwarfism Type II
- Mal de debarquement syndrome (MdDS)
- Malakoplakia
- Male pseudohermaphroditism/mental retardation syndrome, Verloes type
- Malignant Atrophic Papulosis
- Malignant Teratocarcinosarcoma
- Malignant cylindroma
- Malignant eccrine spiradenoma
- Malignant fibrous histiocytoma
- Malignant germ cell tumor
- Malignant hyperthermia
- Malignant hyperthermia arthrogryposis torticollis
- Malignant hyperthermia susceptibility type 1
- Malignant hyperthermia susceptibility type 2
- Malignant hyperthermia susceptibility type 3
- Malignant hyperthermia susceptibility type 4
- Malignant hyperthermia susceptibility type 5
- Malignant hyperthermia susceptibility type 6
- Malignant melanoma, childhood
- Malignant mesothelioma
- Malignant migrating partial seizures in infancy
- Malignant mixed Mullerian tumor
- Malignant paroxysmal ventricular tachycardia
- Malignant peripheral nerve sheath tumor
- Malignant pheochromocytoma
- Malignant variant of Abrikosov's tumor
- Malonic Acidemia
- Malonyl-CoA decarboxylase deficiency
- Malouf syndrome
- Malpuech facial clefting syndrome
- Mandibuloacral dysplasia with type A lipodystrophy
- Mandibuloacral dysplasia with type B lipodystrophy
- Mandibulofacial dysostosis, Treacher Collins type, autosomal recessive
- Mannosidosis
- Mannosidosis, beta A, lysosomal
- Mansonella perstans
- Mansonelliasis
- Mantle cell lymphoma
- Maple Syrup Urine Disease (MSUD)
- Maple syrup urine disease
- Maple syrup urine disease type 1A
- Maple syrup urine disease type 1B
- Maple syrup urine disease type 2
- Maple syrup urine disease, type 3
- Marchiafava Bignami disease
- Marchiafava-Micheli disease
- Marden Walker Syndrome
- Marden-Walker syndrome
- Marfan syndrome
- Marfan syndrome type 2
- Marie Unna congenital hypotrichosis
- Marinesco-Sjogren syndrome
- Marinesco-Sjogren-like syndrome (MSLS)
- Markel Vikkula Mulliken syndrome
- Marles Greenberg Persaud syndrome
- Maroteaux Stanescu Cousin syndrome
- Maroteaux Verloes Stanescu syndrome
- Marphanoid syndrome type De Silva
- Marsden Nyhan Sakati syndrome
- Marshall syndrome
- Marshall-Smith syndrome
- Martinez Monasterio Pinheiro syndrome
- Martsolf syndrome
- Massa Casaer Ceulemans syndrome
- Mastocytic enterocolitis
- Mastocytosis cutaneous with short stature conductive hearing loss and microtia
- Mastroiacovo Gambi Segni syndrome
- Maternal BH4 deficiency
- Maternal PKU
- Maternal hyperphenylalaninemia
- Maternally inherited Leigh syndrome
- Mathieu De Broca Bony syndrome
- Matsoukas Liarikos Giannika syndrome
- Maumenee syndrome
- Maxillofacial dysostosis
- Maxillonasal dysplasia, Binder type
- May-hegglin anomaly
- Mayer-Rokitansky-Kuster-Hauser Syndrome
- McAlister Crane syndrome
- McArdle Disease
- McCallum Macadam Johnston syndrome
- McCune Albright syndrome
- McCune-Albright Syndrome
- McDonough syndrome
- McDowall syndrome
- McGillivray syndrome
- McKusick Kaufman syndrome
- McLain Debakian syndrome
- McPherson Clemens syndrome
- McPherson Robertson Cammarano syndrome
- Meacham Winn Culler syndrome
- Meadows syndrome
- Measles
- Meckel syndrome
- Meckel syndrome type 2
- Meckel syndrome type 3
- Meckel syndrome type1
- Meckel-Gruber syndrome
- Medeira Dennis Donnai syndrome
- Medial Medullary Syndrome
- Median Cleft Upper Lip Cutaneous Polyps
- Median cleft of upper lip with polyps of facial skin and nasal mucosa
- Median nodule of the upper lip
- Mediastinal endodermal sinus tumors
- Medina worm disease
- Medium-chain 3-ketoacyl-coa thiolase deficiency
- Medium-chain acyl-coenzyme A dehydrogenase deficiency
- Medrano Roldan syndrome
- Medullary cystic kidney disease
- Medullary cystic kidney disease 1
- Medullary cystic kidney disease 2
- Medullary sponge kidney
- Meesmann corneal dystrophy
- Megacystis microcolon intestinal hypoperistalsis syndrome
- Megaduodenum and/or megacystis
- Megaepiphyseal dwarfism
- Megalencephalic leukoencephalopathy with subcortical cysts
- Megalencephaly, polymicrogyria, and hydrocephalus (MPPH) syndrome
- Megalocornea mental retardation syndrome
- Megalocytic interstitial nephritis
- Megarbane Jalkh syndrome
- Megarbane syndrome
- Mehes syndrome
- Mehta Lewis Patton syndrome
- Meier Blumberg Imahorn syndrome
- Meier Rotschild syndrome
- Meier-Gorlin syndrome
- Meige Syndrome
- Meigel disease
- Meinecke Pepper syndrome
- Meinecke syndrome
- Melanoma astrocytoma syndrome
- Melanoma of the ciliary body
- Meleda Disease
- Melhem Fahl syndrome
- Melkersson-Rosenthal syndrome
- Melnick-Fraser syndrome
- Melnick-Needles syndrome
- Melorheostosis
- Membranoproliferative glomerulonephritis type 2
- Mendes de Costa syndrome
- Menetrier disease
- Mengel Konigsmark syndrome
- Meniere Disease
- Meningeal angiomatosis cleft hypoplastic left heart
- Meningioma
- Meningioma, spinal
- Meningitis
- Meningocele
- Meningococcal infection
- Meningococcemia
- Meningoencephalocele
- Meningoencephalocele-arthrogryposis-hypoplastic thumb
- Meningomyelocele
- Menkes disease
- Menkes kinky-hair syndrome
- Mental deficiency-epilepsy-endocrine disorders
- Mental mixed retardation deafnes clubbed digits
- Mental retardation Mietens Weber type
- Mental retardation Smith Fineman Myers type
- Mental retardation X-linked Brunner type
- Mental retardation X-linked borderline Maoa metabolism anomaly
- Mental retardation X-linked dysmorphism
- Mental retardation X-linked dystonia dysarthria
- Mental retardation X-linked short stature obesity
- Mental retardation X-linked syndromic 11
- Mental retardation X-linked syndromic 7
- Mental retardation X-linked, South African type
- Mental retardation anophthalmia craniosynostosis
- Mental retardation arachnodactyly hypotonia telangiectasia
- Mental retardation athetosis microphthalmia
- Mental retardation blepharophimosis obesity web neck
- Mental retardation cataracts calcified pinnae myopathy
- Mental retardation coloboma slimness
- Mental retardation dysmorphism hypogonadism diabetes
- Mental retardation epilepsy bulbous nose
- Mental retardation gynecomastia obesity X-linked
- Mental retardation hypocupremia hypobetalipoproteinemia
- Mental retardation hypotonia skin hyperpigmentation
- Mental retardation macrocephaly coarse facies hypotonia
- Mental retardation microcephaly phalangeal facial
- Mental retardation microcephaly unusual facies
- Mental retardation multiple nevi
- Mental retardation myopathy short stature endocrine defect
- Mental retardation nasal hypoplasia obesity genital hypoplasia
- Mental retardation nasal papillomata
- Mental retardation osteosclerosis
- Mental retardation progressive spasticity
- Mental retardation psychosis macroorchidism
- Mental retardation short broad thumbs
- Mental retardation short stature Bombay phenotype
- Mental retardation short stature absent phalanges
- Mental retardation short stature cleft palate unusual facies
- Mental retardation short stature deafness genital
- Mental retardation short stature hand contractures genital anomalies
- Mental retardation short stature heart and skeletal anomalies
- Mental retardation short stature hypertelorism
- Mental retardation short stature microcephaly eye
- Mental retardation short stature ocular and articular anomalies
- Mental retardation short stature scoliosis
- Mental retardation short stature unusual facies
- Mental retardation skeletal dysplasia abducens palsy
- Mental retardation spasticity ectrodactyly
- Mental retardation syndrome, Belgian type
- Mental retardation unusual facies
- Mental retardation unusual facies talipes hand anomalies
- Mental retardation x-linked with cerebellar hypoplasia and distinctive facial appearance
- Mental retardation, X-linked 14
- Mental retardation, X-linked, nonspecific
- Mental retardation, epileptic seizures, hypogonadism and hypogenitalism, microcephaly, and obesity
- Mental retardation, keratoconus, febrile seizures, and sinoatrial block
- Mental retardation, macrocephaly, short stature and craniofacial dysmorphism
- Mental retardation-hypotonic facies syndrome X-linked, 1
- Mental retardation-polydactyly-uncombable hair
- Merkel cell cancer
- Merlob Grunebaum Reisner syndrome
- Merlob syndrome
- Merosin deficient congenital muscular dystrophy
- Mesangial sclerosis, diffuse
- Mesodermal defects lower type
- Mesomelia-synostoses syndrome
- Mesomelic dwarfism cleft palate camptodactyly
- Mesomelic dwarfism of hypoplastic tibia and radius type
- Mesomelic dysplasia Kantaputra type
- Mesomelic dysplasia Savarirayan type
- Mesomelic dysplasia skin dimples
- Mesomelic syndrome Pfeiffer type
- Metachondromatosis
- Metachromatic leukodystrophy
- Metachromatic leukodystrophy due to saposin B deficiency
- Metaphyseal acroscyphodysplasia
- Metaphyseal anadysplasia
- Metaphyseal anadysplasia 2
- Metaphyseal chondrodysplasia Schmid type
- Metaphyseal chondrodysplasia Spahr type
- Metaphyseal chondrodysplasia with cone-shaped epiphyses, normal hair, and normal hands
- Metaphyseal chondrodysplasia, McKusick type
- Metaphyseal chondrodysplasia, others
- Metaphyseal dysostosis mental retardation conductive deafness
- Metaphyseal dysplasia Pyle type
- Metaphyseal dysplasia maxillary hypoplasia brachydactyly
- Metaphyseal dysplasia without hypotrichosis
- Metaphyseal undermodeling, spondylar dysplasia, and overgrowth
- Metastatic insulinoma
- Metatropic dwarfism
- Methacrylic acid toxicity
- Methacrylic aciduria
- Methicillin-resistant Staphylococcus aureus
- Methionine adenosyl transferase deficiency
- Methionine synthase deficiency
- Methylcobalamin deficiency cbl G type
- Methylcobalamin deficiency, cbl E complementation type
- Methylmalonic Acidemia (MMA)
- Methylmalonic acidemia
- Methylmalonic acidemia with homocystinuria
- Methylmalonic aciduria cblA type
- Methylmalonic aciduria cblB type
- Methylmalonic aciduria due to methylmalonyl-coa mutase deficiency
- Methylmalonicacidemia with homocystinuria cbl d
- Methylmalonicaciduria with homocystinuria cbl f
- Methylmalonyl-Coenzyme A mutase deficiency
- Mevalonic aciduria
- megalencephaly-capillary malformation-polymicrogyria